Showing 1–50 of 88 results for author: Dmitriev, A

Millisecond optical coherence and strong collective coupling in an integrated telecom rare-earth photonic platform

Authors: Kah Jen Wo, Pavel A. Dmitriev, Karthik Dasigi, Fumiya Hanamura, Steven Touzard

Abstract: Long-range quantum network nodes require the combination of strong light-matter coupling, long coherence times and in situ spectral control at telecom wavelengths. The coherence of erbium in integrated devices is held back by its hosts, which do not simultaneously provide the weakly magnetic nuclear-spin environment and the well-defined substitutional sites found in coherence-optimised bulk crysta… ▽ More Long-range quantum network nodes require the combination of strong light-matter coupling, long coherence times and in situ spectral control at telecom wavelengths. The coherence of erbium in integrated devices is held back by its hosts, which do not simultaneously provide the weakly magnetic nuclear-spin environment and the well-defined substitutional sites found in coherence-optimised bulk crystals. Here we bring such an optimised crystal onto a photonic chip, by bonding an Er${^{3+}}$:CaWO${_{4}}$ host without an adhesive interlayer to a high-${Q}$ electro-optically tuneable thin-film lithium niobate microring resonator. At an effective temperature of ${75}$ mK and a field of only ${0.2}$ T, the bonded ensemble retains an effective homogeneous linewidth of ${289\pm34}$ Hz (${T_\text{M}=1.10\pm0.13}$ ms), with spectral diffusion proceeding at ${86\pm18}$ Hz and saturating at ${1.5\pm0.2}$ kHz. Electro-optically tuning the resonator through the erbium optical transition resolves an avoided crossing with a collective cooperativity of ${C=6.7\pm0.4}$. Exploiting superhyperfine coupling to the host's ${^{183}}$W nuclear spins, we store and retrieve optical phase information over ${5}$ s with a visibility of ${0.935\pm0.015}$. Strong collective coupling, millisecond coherence and in situ spectral tuning in a single device thus establish heterogeneous integration leveraging coherence-optimised hosts as a route to scalable telecom quantum networks. △ Less

Submitted 8 August, 2026; originally announced August 2026.

Sideband fingerprints of antibunched light in cascaded quantum wave mixing

Authors: R. D. Ivanovskikh, W. V. Pogosov, A. A. Elistratov, A. Yu. Dmitriev, T. R. Sabirov, A. V. Vasenin, S. A. Gunin, O. V. Astafiev

Abstract: Quantum wave mixing on a single superconducting qubit produces a hierarchy of coherent side peaks associated with elastic multiphoton scattering pathways. In a cascaded source--probe geometry these pathways become sensitive to the photon statistics of the radiation emitted by the source qubit. We develop an analytical theory of this effect starting from the cascaded master equation in the weak-dri… ▽ More Quantum wave mixing on a single superconducting qubit produces a hierarchy of coherent side peaks associated with elastic multiphoton scattering pathways. In a cascaded source--probe geometry these pathways become sensitive to the photon statistics of the radiation emitted by the source qubit. We develop an analytical theory of this effect starting from the cascaded master equation in the weak-driving regime. In the coherent-filtering limit $γ_{\rm s}\ggγ_{\rm pr}$, the standard coherent--coherent wave-mixing hierarchy is recovered. In the opposite limit $γ_{\rm pr}\ggγ_{\rm s}$, side peaks associated with multiphoton absorption from the antibunched source field are parametrically suppressed. Numerical solutions confirm the analytical scaling laws. The resulting sideband hierarchy provides a frequency-domain fingerprint of antibunched itinerant microwave light. △ Less

Submitted 25 May, 2026; originally announced May 2026.

Comments: 13 pages

Photon pairs, squeezed light and the quantum wave mixing effect in a cascaded qubit system

Authors: R. D. Ivanovskikh, W. V. Pogosov, A. A. Elistratov, S. V. Remizov, A. Yu. Dmitriev, T. R. Sabirov, A. V. Vasenin, S. A. Gunin, O. V. Astafiev

Abstract: We develop a theoretical description of quantum wave mixing (QWM) in a cascaded waveguide-QED system of two superconducting qubits, where the probe is driven by an external coherent tone and by the resonance fluorescence of a strongly driven source qubit. Starting from the field correlation functions of the source emission, we derive an effective master-equation treatment for the probe and identif… ▽ More We develop a theoretical description of quantum wave mixing (QWM) in a cascaded waveguide-QED system of two superconducting qubits, where the probe is driven by an external coherent tone and by the resonance fluorescence of a strongly driven source qubit. Starting from the field correlation functions of the source emission, we derive an effective master-equation treatment for the probe and identify the regime in which the incident fluorescence is characterized by anomalous correlations. When the coherent Rayleigh component of the source spectrum is suppressed, the probe equations of motion become equivalent to those for a qubit driven by a coherent tone and broadband squeezed light. This equivalence implies a selection rule for the peaks of the QWM spectrum, with a strong suppression of sidebands associated with processes involving an odd number of photons taken from the source field. Numerical simulations of the full cascaded two-qubit model for different ratios of radiative decay rates unambiguously confirm the participation of correlated photon pairs in QWM processes. The current research illustrates that the analysis of peak amplitudes can be used to probe photon statistics in the incident nonclassical field. △ Less

Submitted 9 April, 2026; originally announced April 2026.

Comments: 10 pages

Giant bias-free nonreciprocity for unpolarized light via synthetic motion

Authors: L. M. Máñez-Espina, B. Amrahi, I. Faniayeu, R. Cichelero, A. Dmitriev, A. Díaz-Rubio, V. S. Asadchy

Abstract: Reciprocity breaking at optical frequencies typically relies on bulky magnets, dynamic modulation, or nonlinearities, all of which hinder chip-scale integration and the handling of unpolarised light. We introduce a fully passive, subwavelength metasurface that achieves polarisation-insensitive one-way transparency by combining self-magnetised ferrite nanodisks in a vortex state with symmetry-prote… ▽ More Reciprocity breaking at optical frequencies typically relies on bulky magnets, dynamic modulation, or nonlinearities, all of which hinder chip-scale integration and the handling of unpolarised light. We introduce a fully passive, subwavelength metasurface that achieves polarisation-insensitive one-way transparency by combining self-magnetised ferrite nanodisks in a vortex state with symmetry-protected quasi-bound states in the continuum. The metasurface exhibits a pure synthetic moving-medium response at optical frequencies, yielding giant nonreciprocal directional dichroism. We report near-unity values for both the transmittance contrast and the emissivity-to-absorptivity ratio with experimentally widely available ferrite materials, all under unpolarised illumination and without external bias. Using temporal coupled-mode theory, we identify the design conditions necessary to maximise directional dichroism: critical coupling, Huygens-type resonance overlap, and strong inter-mode coupling. Furthermore, we propose a deterministic, stamp-assisted protocol for imprinting arbitrary, uniform, or patterned vortex configurations across large arrays of nanodisk meta-atoms, enabling scalable fabrication. This work establishes a practical route toward compact nonreciprocal photonics with applications in photonic gyrators, nonreciprocal wavefront engineering, and nonreciprocal solar cell technologies. △ Less

Submitted 15 October, 2025; originally announced October 2025.

Comments: 17 pages, 5 figures

Quantum-Limited Optical Vector Analysis

Authors: Karthik Dasigi, Pavel A. Dmitriev, Kah Jen Wo, Fumiya Hanamura, Lingda Kong, Steven Touzard

Abstract: Optical Vector Analysers (OVA) are critical for emerging technologies such as integrated photonics and optical positioning. Achieving a sensitivity near the Standard Quantum Limit (SQL) while acquiring a wide spectrum allows an accurate measurement of targets that are fragile, non-linear, or that scatter most of the probe light away. Existing OVAs operate with a sensitivity orders of magnitude bel… ▽ More Optical Vector Analysers (OVA) are critical for emerging technologies such as integrated photonics and optical positioning. Achieving a sensitivity near the Standard Quantum Limit (SQL) while acquiring a wide spectrum allows an accurate measurement of targets that are fragile, non-linear, or that scatter most of the probe light away. Existing OVAs operate with a sensitivity orders of magnitude below the SQL. In this paper, we use a free-running interferometer with a frequency range of 20 THz as an OVA. We introduce novel methods to mitigate the phase noise and obtain a unit signal-to-noise ratio for powers at the fW level. We apply this technique towards quantifying the fabrication quality of microring resonators in thin-film Lithium Niobate. Our characterisation yields a signal-to-noise ratio above 1 with much less than 1 circulating photon and reveals a quality factor above 5 millions, unambiguously attributed to low internal losses. △ Less

Submitted 30 September, 2025; originally announced September 2025.

Comments: 5 pages, 4 figures

Deeply Subwavelength Blue-Range Nanolaser

Authors: Daria Khemelevskaia, Nikolai Solodovchenko, Elizaveta Sapozhnikova, Igor Chestnov, Alexey Dmitriev, Vanik Shahnazaryan, Denis Baranov, Sergey Makarov

Abstract: Modern high-definition display and augmented reality technologies require the development of ultracompact micro- and nano-pixels with colors covering the full gamut and high brightness. In this regard, lasing nano-pixels emitting light in the spectral range 400-700 nm are highly demanded. Despite progress in red, green, and ultraviolet nanolasers, the demonstrated blue-range (400-500 nm) single-pa… ▽ More Modern high-definition display and augmented reality technologies require the development of ultracompact micro- and nano-pixels with colors covering the full gamut and high brightness. In this regard, lasing nano-pixels emitting light in the spectral range 400-700 nm are highly demanded. Despite progress in red, green, and ultraviolet nanolasers, the demonstrated blue-range (400-500 nm) single-particle-based lasers are still not subwavelength yet. Here we fabricate CsPbCl$_3$ cubic-shaped single-crystal nanolasers on a silver substrate by wet chemistry synthesis, producing their size range around 100-500 nm, where the nanoparticle with sizes 0.145$μ$m$\times$0.195$μ$m$\times$0.19$μ$m and volume 0.005 $μ$m$^3$ (i.e. $\simλ^3$/13) is the smallest nanolaser among the lasers operating in the blue range reported so far, with emission wavelength around $λ\approx 415$ nm. Experimental results at a temperature of 80 K and theoretical modeling show that the CsPbCl$_3$ nanolaser is a polaritonic laser where exciton-polaritons are strongly coupled with Mie resonances enhanced by the metallic substrate. As a result, the combination of the strong excitonic response of CsPbCl$_3$ materials, its high crystalline quality, and optimized optical resonant properties resulting in a population-inversion-free lasing regime are the key factors making the proposed nanolaser design superior among previously reported ones in the blue spectral range. △ Less

Submitted 16 September, 2025; originally announced September 2025.

Realization of the Tellegen Effect in Resonant Optical Metasurfaces

Authors: Shadi Safaei Jazi, Ihar Faniayeu, Rafael Cichelero, Nikolai Kuznetsov, Sebastiaan van Dijken, Shanhui Fan, Alexandre Dmitriev, Viktar Asadchy

Abstract: The nonreciprocal magnetoelectric effect in Tellegen materials enables exotic phenomena such as axion-modified electrodynamics and fosters the development of magnet-free nonreciprocal media. As the nonreciprocal counterpart to the well-known chiral electromagnetic response, it offers a parallel framework in which many concepts developed for chiral materials can be translated to Tellegen media, pot… ▽ More The nonreciprocal magnetoelectric effect in Tellegen materials enables exotic phenomena such as axion-modified electrodynamics and fosters the development of magnet-free nonreciprocal media. As the nonreciprocal counterpart to the well-known chiral electromagnetic response, it offers a parallel framework in which many concepts developed for chiral materials can be translated to Tellegen media, potentially unlocking new avenues for fundamental studies and applications. Although predicted over 75 years ago and observed in only a handful of natural materials with very low strength, the strong optical Tellegen effect has remained experimentally elusive. Here, we report the first experimental demonstration of a resonant optical diagonal Tellegen effect in a metasurface, showcasing a response that is 100 times greater than that of any known natural material. This optical metasurface, consisting of randomly distributed cobalt-silicon nanoscatterers with strong shape anisotropy, utilizes spontaneous magnetization to achieve a robust Tellegen effect without the need for an external magnetic field. In addition to the Tellegen response, the metasurface exhibits both gyroelectric and gyromagnetic effects, contributing to nonreciprocal cross-polarized light reflection. We introduce a technique to independently extract the amplitudes of these three effects using conventional magneto-optical single-side-illumination measurements. The observation of the resonant Tellegen effects in the optical frequency range may lead to the experimental observation of axionic electrodynamics and compact bias-free nonreciprocal optical devices. △ Less

Submitted 5 March, 2026; v1 submitted 28 March, 2025; originally announced March 2025.

Journal ref: eLight 6, 8 (2026)

Highly stable aluminum air-bridges with stiffeners

Authors: Aleksey N. Bolgar, Daria A. Kalacheva, Viktor B. Lubsanov, Aleksei Yu. Dmitriev, Evgenia S. Alekseeva, Evgeny V. Korostylev, Oleg V. Astafiev

Abstract: Air-bridges play a critical role in the performance of microwave circuits integrated with superconducting quantum bits, and their mechanical stability is predominant for reliable operation. This study is devoted to the technological issues that lead to air-bridge instability. We propose an optimized bridge geometry designed to enhance mechanical resilience. Through systematic testing, we establish… ▽ More Air-bridges play a critical role in the performance of microwave circuits integrated with superconducting quantum bits, and their mechanical stability is predominant for reliable operation. This study is devoted to the technological issues that lead to air-bridge instability. We propose an optimized bridge geometry designed to enhance mechanical resilience. Through systematic testing, we established that bridges incorporating this novel geometry achieved complete stability for lengths up to 170 micrometers in our technological processes. The findings provide an insight into the problem and a practical solution for technologists that faced with the challenges of air-bridge stability. The implementation of our technology has the potential to significantly improve the mechanical robustness of air-bridges in multi-qubit circuits for quantum computation. △ Less

Submitted 30 October, 2024; originally announced October 2024.

Direct experimental observation of sub-poissonian photon statistics by means of multi-photon scattering on a two-level system

Authors: A. Yu. Dmitriev, A. V. Vasenin, S. A. Gunin, S. V. Remizov, A. A. Elistratov, W. V. Pogosov, O. V. Astafiev

Abstract: A cascade of two-level superconducting artificial atoms -- a source and a probe -- strongly coupled to a semi-infinite waveguide is a promising tool for observing nontrivial phenomena in quantum nonlinear optics. The probe atom can scatter an antibunched radiation emitted from the source, thereby generating a field with specific properties. We experimentally demonstrate wave mixing between nonclas… ▽ More A cascade of two-level superconducting artificial atoms -- a source and a probe -- strongly coupled to a semi-infinite waveguide is a promising tool for observing nontrivial phenomena in quantum nonlinear optics. The probe atom can scatter an antibunched radiation emitted from the source, thereby generating a field with specific properties. We experimentally demonstrate wave mixing between nonclassical light from the coherently cw-pumped source and another coherent wave acting on the probe. We observe unique features in the wave mixing stationary spectrum which differs from mixing spectrum of two classical waves on the probe. These features are well described by adapting the theory for a strongly coupled cascaded system of two atoms. We further analyze the theory to predict non-classical mixing spectra for various ratios of atoms' radiative constants. Both experimental and numerical results confirm the domination of multi-photon scattering process with only a single photon from the source. We evaluate entanglement of atoms in the quasistationary state and illustrate the connection between the expected second-order correlation function of source's field and wave mixing side peaks corresponding to a certain number of scattered photons. △ Less

Submitted 17 September, 2024; originally announced September 2024.

Comments: 10 pages, 10 figures, RevTex 4.2

Journal ref: Phys. Rev. A 111, 043715 (2025)

A rechargeable AA battery supporting Qi wireless charging

Authors: Alexey A. Dmitriev, Egor D. Demeshko, Danil A. Chernomorov, Andrei A. Mineev, Oleg I. Burmistrov, Sergey S. Ermakov, Alina D. Rozenblit, Pavel S. Seregin, Nikita A. Olekhno

Abstract: Wireless power transfer is one of the key drivers in modern consumer electronics, as it allows one to enhance the convenience and usability of many devices. However, in most cases, wireless charging is accessible only to devices with incorporated receivers or at least to gadgets with standard charging connectors, such as USB Type-C, that allow to attach an external receiver. We propose a rechargea… ▽ More Wireless power transfer is one of the key drivers in modern consumer electronics, as it allows one to enhance the convenience and usability of many devices. However, in most cases, wireless charging is accessible only to devices with incorporated receivers or at least to gadgets with standard charging connectors, such as USB Type-C, that allow to attach an external receiver. We propose a rechargeable battery that has the size and output voltage of a standard AA battery but supports wireless power transfer from charging stations of the widely used Qi standard. The proposed design uses a series resonant circuit with a curved receiving coil, as well as load modulation using detuning capacitors switched by a microcontroller unit to implement a receiver compatible with the Qi Baseline protocol. It also utilizes a number of DC-DC converters to store energy in a Li-ion cell and convert it to the 1.5 V voltage level. Our design is supported by numerical simulations of magnetic field distributions and scattering parameters of the introduced battery coupled to a planar transmitting coil. The performance of the proposed battery has been studied experimentally, including measurements of the maximal distance between the battery and a charging station that allows wireless charging at various rotation angles and the charge curve. The developed battery design facilitates the addition of wireless charging functionality to a wide range of electronic devices in a universal way. △ Less

Submitted 5 July, 2026; v1 submitted 19 August, 2024; originally announced August 2024.

Comments: 11 pages, 10 figures + Supplementary Materials

Disordered Optical Metasurfaces: Basics, Properties, and Applications

Authors: P. Lalanne, M Chen, C. Rockstuhl, A. Sprafke, A. Dmitriev, K. Vynck

Abstract: Optical metasurfaces are conventionally viewed as organized flat arrays of photonic or plasmonic nanoresonators, also called metaatoms. These metasurfaces are typically highly ordered and fabricated with precision using expensive tools. However, the inherent imperfections in large-scale nanophotonic devices, along with recent advances in bottom-up nanofabrication techniques and design strategies,… ▽ More Optical metasurfaces are conventionally viewed as organized flat arrays of photonic or plasmonic nanoresonators, also called metaatoms. These metasurfaces are typically highly ordered and fabricated with precision using expensive tools. However, the inherent imperfections in large-scale nanophotonic devices, along with recent advances in bottom-up nanofabrication techniques and design strategies, have highlighted the potential benefits of incorporating disorder to achieve specific optical functionalities. This review offers an overview of the key theoretical, numerical, and experimental aspects related to the exploration of disordered optical metasurfaces. It introduces fundamental concepts of light scattering by disordered metasurfaces and outlines theoretical and numerical methodologies for analyzing their optical behavior. Various fabrication techniques are discussed, highlighting the types of disorder they deliver and their achievable precision level. The review also explores critical applications of disordered optical metasurfaces, such as light manipulation in thin film materials and the design of structural colors and visual appearances. Finally, the article offers perspectives on the burgeoning future research in this field. Disordered optical metasurfaces offer a promising alternative to their ordered counterparts, often delivering unique functionalities or enhanced performance. They present a particularly exciting opportunity in applications demanding large-scale implementation, such as sustainable renewable energy systems, as well as aesthetically vibrant coatings for luxury goods and architectural designs. △ Less

Submitted 6 March, 2025; v1 submitted 18 August, 2024; originally announced August 2024.

Comments: review article: 56 pages, 15 figures (accepted in Advances in Optics and Photonics)

Journal ref: Advances in Optics and Photonics Vol. 17, Issue 1, pp. 45-113 (2025)

Bayesian Approach to Particles Identification in the MPD Experimen

Authors: V. A. Babkin, V. M. Baryshnikov, M. G. Buryakov, A. S. Burdyko, S. G. Buzin, A. V. Dmitriev, V. I. Dronik, P. O. Dulov, A. A. Fedyunin, V. M. Golovatyuk, E. Yu. Kidanova, S. P. Lobastov, A. D. Pyatigor, M. M. Rumyantsev, K. A. Vokhmyanina

Abstract: Identification of particles generated by ion collisions in the NICA collider is one of the basic functions of the Multipurpose Detector (MPD). The main means of identification in MPD are the time-of-flight system (TOF) and the time-projection chamber (TPC). The article considers the optimization of the algorithms of particles identification by these systems. Under certain conditions, the use of th… ▽ More Identification of particles generated by ion collisions in the NICA collider is one of the basic functions of the Multipurpose Detector (MPD). The main means of identification in MPD are the time-of-flight system (TOF) and the time-projection chamber (TPC). The article considers the optimization of the algorithms of particles identification by these systems. Under certain conditions, the use of the statistical Bayesian approach has made it possible to achieve an optimal ratio of the efficiency of particle identification and contamination by incorrectly defined particles. △ Less

Submitted 17 May, 2024; originally announced June 2024.

Sensitivity and control of a 6-axis fused-silica seismometer

Authors: Jiri Smetana, Amit Singh Ubhi, Emilia Chick, Leonid Prokhorov, John Bryant, Artemiy Dmitriev, Alex Gill, Lari Koponen, Haixing Miao, Alan V. Cumming, Giles Hammond, Valery Frolov, Richard Mittleman, Peter Fritchel, Denis Martynov

Abstract: We present a pair of seismometers capable of measurement in all six axes of rigid motion. The vacuum-compatible devices implement compact interferometric displacement sensors to surpass the sensitivity of typical electrical readout schemes. Together with the capability to subtract the sensitivity-limiting coupling of ground tilt into horizontal motion, our seismometers can widen the sensing band t… ▽ More We present a pair of seismometers capable of measurement in all six axes of rigid motion. The vacuum-compatible devices implement compact interferometric displacement sensors to surpass the sensitivity of typical electrical readout schemes. Together with the capability to subtract the sensitivity-limiting coupling of ground tilt into horizontal motion, our seismometers can widen the sensing band towards mHz frequencies. This has notable applications across a range of fields requiring access to low-frequency signals, such as seismology and climate research. We particularly highlight their potential application in gravitational-wave observatories (LIGO) in improving their observation capability of intermediate-mass black holes ($\sim 1000\,M_\odot$). The sensors are based on a near-monolithic fused-silica design consisting of a fused-silica mass and fibre, showing improved stability and robustness to tilt drifts, alignment, and control compared to all-metal or mixed metal-silica designs. We demonstrate tilt sensitivity that surpasses the best commercial alternatives in a significantly reduced footprint compared to our previous iterations of these sensors. △ Less

Submitted 6 January, 2025; v1 submitted 22 May, 2024; originally announced May 2024.

Comments: 12 pages, 3 figures

The BM@N spectrometer at the NICA accelerator complex

Authors: S. Afanasiev, G. Agakishiev, E. Aleksandrov, I. Aleksandrov, P. Alekseev, K. Alishina, V. Astakhov, E. Atkin, T. Aushev, V. Azorskiy, V. Babkin, N. Balashov, R. Barak, A. Baranov, D. Baranov, N. Baranova, N. Barbashina, M. Baznat, S. Bazylev, M. Belov, D. Blau, V. Bocharnikov, G. Bogdanova, A. Bolozdynya, E. Bondar , et al. (187 additional authors not shown)

Abstract: BM@N (Baryonic Matter at Nuclotron) is the first experiment operating and taking data at the Nuclotron/NICA ion-accelerating complex.The aim of the BM@N experiment is to study interactions of relativistic heavy-ion beams with fixed targets. We present a technical description of the BM@N spectrometer including all its subsystems. BM@N (Baryonic Matter at Nuclotron) is the first experiment operating and taking data at the Nuclotron/NICA ion-accelerating complex.The aim of the BM@N experiment is to study interactions of relativistic heavy-ion beams with fixed targets. We present a technical description of the BM@N spectrometer including all its subsystems. △ Less

Submitted 11 March, 2024; v1 submitted 29 December, 2023; originally announced December 2023.

Comments: 34 pages, 47 figures, 6 tables

Nonlinear helicity anomalies in the cyclotron resonance photoresistance of two-dimensional electron systems

Authors: Erwin Mönch, Sophia Schweiss, Ivan Yahniuk, Maxim L. Savchenko, Ivan A. Dmitriev, Alexey Shuvaev, Andrei Pimenov, Dieter Schuh, Dominique Bougeard, Sergey D. Ganichev

Abstract: Our studies of the cyclotron resonance (CR) photoresistance in GaAs-based two-dimensional electron systems (2DES) reveal an anomalously low sensitivity to the helicity of the incoming circularly polarized terahertz radiation. We find that this anomaly is strongly intensity dependent, and the ratio of the low-temperature photoresistance signals for the CR-active (CRA) and CR-inactive (CRI) polariti… ▽ More Our studies of the cyclotron resonance (CR) photoresistance in GaAs-based two-dimensional electron systems (2DES) reveal an anomalously low sensitivity to the helicity of the incoming circularly polarized terahertz radiation. We find that this anomaly is strongly intensity dependent, and the ratio of the low-temperature photoresistance signals for the CR-active (CRA) and CR-inactive (CRI) polarities of magnetic field increases with lowering power, but, nevertheless, remains substantially lower than expected from conventional theory assuming interaction of the plane electromagnetic wave with the uniform 2DES. Our analysis shows that all data can be well described by the nonlinear CR-enhanced electron gas heating in both CRA and CRI regimes. This description, however, requires a source of anomalous absorption of radiation in the CRI regime. It can stem from evanescent electromagnetic fields originating from the near-field diffraction within or in the vicinity of the quantum well hosting the 2DES. △ Less

Submitted 9 November, 2023; originally announced November 2023.

Comments: 15 pages, 8 figures

Minireview on Disordered Optical Metasurfaces

Authors: P. Lalanne, A. Dmitriev, C. Rockstuhl, A. Sprafke, K. Vynck

Abstract: The use of coherent wave phenomena to enhance device performance is a cornerstone of modern optics. In juxtaposition to (locally) periodic metasurfaces, their disordered counterparts exhibit an interplay of destructive and constructive interferences occurring at the same spatial and spectral frequencies. This attribute provides disordered metasurfaces with a remarkable degree of flexibility, setti… ▽ More The use of coherent wave phenomena to enhance device performance is a cornerstone of modern optics. In juxtaposition to (locally) periodic metasurfaces, their disordered counterparts exhibit an interplay of destructive and constructive interferences occurring at the same spatial and spectral frequencies. This attribute provides disordered metasurfaces with a remarkable degree of flexibility, setting them apart from the constraints of periodic arrangements. Hereafter, we provide a concise overview of the cutting-edge developments and offer insights into the forthcoming research in this dynamic field. △ Less

Submitted 18 November, 2023; v1 submitted 22 October, 2023; originally announced October 2023.

Journal ref: Appl. Phys. Lett. 124, 260701 (2024)

Evolution of coherent waves driving a single artificial atom

Authors: A. V. Vasenin, Sh. V. Kadyrmetov, A. N. Bolgar, A. Yu. Dmitriev, O. V. Astafiev

Abstract: An electromagnetic wave propagating through a waveguide with a strongly coupled superconducting artificial two-level atom exhibits an evolving superposition with the atom. The Rabi oscillations in the atom result from a single excitation-relaxation, corresponding to photon absorption and stimulated emission from/to the field. In this study, we investigate the time-dependent behavior of the transmi… ▽ More An electromagnetic wave propagating through a waveguide with a strongly coupled superconducting artificial two-level atom exhibits an evolving superposition with the atom. The Rabi oscillations in the atom result from a single excitation-relaxation, corresponding to photon absorption and stimulated emission from/to the field. In this study, we investigate the time-dependent behavior of the transmitted field and extract its spectra. The scattered fields are described using input-output theory. We demonstrate that the time evolution of the propagating fields, due to interaction, encapsulates all information about the atom. Additionally, we deduce the dynamics of the incoherent radiation component from the measured first-order correlation function of the field. △ Less

Submitted 6 September, 2023; v1 submitted 4 September, 2023; originally announced September 2023.

Comments: Main text: 6 pages, 4 figures; Supplemental Material: 4 pages, 1 figure; updated comment

Tuning of resonant doublets in coupled optical cavities

Authors: Riccardo Maggiore, Artemiy Dmitriev, Andreas Freise, Mischa Sallé

Abstract: The mode profile of a coupled optical cavity often exhibits a resonant doublet, which arises from the strong coupling between its sub-cavities. Traditional readout methods rely on setting fields of different frequencies to be resonant in either sub-cavity, which is challenging in the case of strong coupling. In this regime, the coupled cavity behaves as a single resonator, and a field must be reso… ▽ More The mode profile of a coupled optical cavity often exhibits a resonant doublet, which arises from the strong coupling between its sub-cavities. Traditional readout methods rely on setting fields of different frequencies to be resonant in either sub-cavity, which is challenging in the case of strong coupling. In this regime, the coupled cavity behaves as a single resonator, and a field must be resonant in all its parts. Consequently, specialized sensing schemes are necessary to control strongly coupled cavities. To address this issue, we propose a novel technique for the relative measurement of the degrees of freedom of a strongly coupled cavity. Our approach enables simultaneous frequency stabilization and fine-tuning of frequency splitting in the resonant doublet. Overall, our proposed technique offers a promising solution to control the properties of coupled cavities, facilitating advanced applications in the fields of gravitational-wave detection, quantum cavity optomechanics, and other related areas. △ Less

Submitted 3 August, 2023; originally announced August 2023.

Retardaion-induced exceptional point

Authors: Alexey A. Dmitriev, Mikhail V. Rybin

Abstract: Exceptional points in an optical dimer of spheres, which have the same size and operate in the spectral region of the dipolar resonance, are considered. By choosing different materials of these spheres, we can offset the radiative loss and create a gain-loss contrast to achieve a parity-time (PT)-symmetric dimer. In this case, an exceptional point corresponds to the point where the PT symmetry is… ▽ More Exceptional points in an optical dimer of spheres, which have the same size and operate in the spectral region of the dipolar resonance, are considered. By choosing different materials of these spheres, we can offset the radiative loss and create a gain-loss contrast to achieve a parity-time (PT)-symmetric dimer. In this case, an exceptional point corresponds to the point where the PT symmetry is broken. At the same time, if we consider a symmetric dimer, where both spheres are made of the same material (which may have a purely real dielectric constant), exceptional points occurring due to the radiative loss non-Hermiticity can also be observed. We study the transition between the two regimes and demonstrate that the exceptional point emerges due to the retardative nature of the coupling between the spheres, which makes the equation for eigenfrequencies nonlinear and allows it to have nontrivial solutions even when there is no contrast between the spheres. △ Less

Submitted 27 July, 2023; originally announced July 2023.

Comments: 9 pages, 5 figures

Journal ref: Phys. Rev. A 108 (2023) 013518

Design and sensitivity of a 6-axis seismometer for gravitational wave observatories

Authors: Leonid Prokhorov, Sam Cooper, Amit Singh Ubhi, Conor Mow-Lowry, John Bryant, Artemiy Dmitriev, Chiara Di Fronzo, Christopher J. Collins, Alex Gill, Alexandra Mitchell, Joscha Heinze, Jiri Smetana, Tianliang Yan, Alan V. Cumming, Giles Hammond, Denis Martynov

Abstract: We present the design, control system, and noise analysis of a 6-axis seismometer comprising a mass suspended by a single fused silica fibre. We utilise custom-made, compact Michelson interferometers for the readout of the mass motion relative to the table and successfully overcome the sensitivity of existing commercial seismometers by over an order of magnitude in the angular degrees of freedom.… ▽ More We present the design, control system, and noise analysis of a 6-axis seismometer comprising a mass suspended by a single fused silica fibre. We utilise custom-made, compact Michelson interferometers for the readout of the mass motion relative to the table and successfully overcome the sensitivity of existing commercial seismometers by over an order of magnitude in the angular degrees of freedom. We develop the sensor for gravitational-wave observatories, such as LIGO, Virgo, and KAGRA, to help them observe intermediate-mass black holes, increase their duty cycle, and improve localisation of sources. Our control system and its achieved sensitivity makes the sensor suitable for other fundamental physics experiments, such as tests of semiclassical gravity, searches for bosonic dark matter, and studies of the Casimir force. △ Less

Submitted 24 July, 2023; originally announced July 2023.

Optical Tellegen metamaterial with spontaneous magnetization

Authors: S. S. Jazi, I. Faniayeu, R. Cichelero, D. C. Tzarouchis, M. M. Asgari, A. Dmitriev, S. Fan, V. Asadchy

Abstract: The nonreciprocal magnetoelectric effect, also known as the Tellegen effect, promises a number of groundbreaking phenomena connected to fundamental (e.g., electrodynamics of axion and relativistic matter) and applied physics (e.g., magnetless isolators). We propose a three-dimensional metamaterial with an isotropic and resonant Tellegen response in the visible frequency range. The metamaterial is… ▽ More The nonreciprocal magnetoelectric effect, also known as the Tellegen effect, promises a number of groundbreaking phenomena connected to fundamental (e.g., electrodynamics of axion and relativistic matter) and applied physics (e.g., magnetless isolators). We propose a three-dimensional metamaterial with an isotropic and resonant Tellegen response in the visible frequency range. The metamaterial is formed by randomly oriented bi-material nanocylinders in a host medium. Each nanocylinder consists of a ferromagnet in a single-domain magnetic state and a high-permittivity dielectric operating near the magnetic Mie-type resonance. The proposed metamaterial requires no external magnetic bias and operates on the spontaneous magnetization of the nanocylinders. By leveraging the emerging magnetic Weyl semimetals, we further show how a giant bulk effective magnetoelectric effect can be achieved in a proposed metamaterial, exceeding that of natural materials by almost four orders of magnitude. △ Less

Submitted 18 July, 2023; originally announced July 2023.

Comments: 11 pages, 4 figures

Journal ref: Nat Commun 15, 1293 (2024)

Polariton lasing in Mie-resonant perovskite nanocavity

Authors: M. A. Masharin, D. Khmelevskaia, V. I. Kondratiev, D. I. Markina, A. D. Utyushev, D. M. Dolgintsev, A. D. Dmitriev, V. A. Shahnazaryan, A. P. Pushkarev, F. Isik, I. V. Iorsh, I. A. Shelykh, H. V. Demir, A. K. Samusev, S. V. Makarov

Abstract: Deeply subwavelength lasers (or nanolasers) are highly demanded for compact on-chip bioimaging and sensing at the nanoscale. One of the main obstacles for the development of single-particle nanolasers with all three dimensions shorter than the emitting wavelength in the visible range is the high lasing thresholds and the resulting overheating. Here we exploit exciton-polariton condensation and mir… ▽ More Deeply subwavelength lasers (or nanolasers) are highly demanded for compact on-chip bioimaging and sensing at the nanoscale. One of the main obstacles for the development of single-particle nanolasers with all three dimensions shorter than the emitting wavelength in the visible range is the high lasing thresholds and the resulting overheating. Here we exploit exciton-polariton condensation and mirror-image Mie modes in a cuboid CsPbBr$_3$ nanoparticle to achieve coherent emission at the visible wavelength of around 0.53~$μ$m from its ultra-small ($\approx$0.007$μ$m$^3$ or $\approxλ^3$/20) semiconductor nanocavity. The polaritonic nature of the emission from the nanocavity localized in all three dimensions is proven by direct comparison with corresponding one-dimensional and two-dimensional waveguiding systems with similar material parameters. Such a deeply subwavelength nanolaser is enabled not only by the high values for exciton binding energy ($\approx$35 meV), refractive index ($>$2.5 at low temperature), and luminescence quantum yield of CsPbBr$_3$, but also by the optimization of polaritons condensation on the Mie resonances. Moreover, the key parameters for optimal lasing conditions are intermode free spectral range and phonons spectrum in CsPbBr$_3$, which govern polaritons condensation path. Such chemically synthesized colloidal CsPbBr$_3$ nanolasers can be easily deposited on arbitrary surfaces, which makes them a versatile tool for integration with various on-chip systems. △ Less

Submitted 22 May, 2023; originally announced May 2023.

Comments: 29 pages, 19 Figures

Numerical Study of Free-Surface Electrohydrodynamic Wave Turbulence

Authors: Igor A. Dmitriev, Evgeny A. Kochurin, Nikolay M. Zubarev

Abstract: Direct numerical simulation of threedimensional chaotic motion of a dielectric liquid with a free surface under the action of external horizontal electric field is carried out. The numerical model takes into account the effects of surface tension, viscosity, and external isotropic random forcing acting at large scales. A transition from dispersive capillary wave turbulence to quasi-isotropic nondi… ▽ More Direct numerical simulation of threedimensional chaotic motion of a dielectric liquid with a free surface under the action of external horizontal electric field is carried out. The numerical model takes into account the effects of surface tension, viscosity, and external isotropic random forcing acting at large scales. A transition from dispersive capillary wave turbulence to quasi-isotropic nondispersive EHD surface turbulence with increase of the external electric field strength is numerically observed for the first time. At the regime of developed EHD wave turbulence, the total electrical energy is found to be much greater than the energy of capillary waves, i.e., electrohydrodynamic effects play a dominant role. At the same time, anisotropic effects are detected that lead to the generation of capillary wave packets traveling perpendicular to the external field direction. Despite the revealed anisotropy, the calculated spectrum of EHD wave turbulence is in very good agreement with the analytical spectrum obtained on the basis of dimensional analysis of weak turbulence spectra. △ Less

Submitted 13 March, 2023; v1 submitted 10 March, 2023; originally announced March 2023.

Comments: 7 pages,7 figures

Journal ref: IEEE Transactions on Dielectrics and Electrical Insulation (2023)

Design of a tabletop interferometer with quantum amplification

Authors: Jiri Smetana, Artemiy Dmitriev, Chunnong Zhao, Haixing Miao, Denis Martynov

Abstract: The sensitivity of laser interferometers is fundamentally limited by the quantum nature of light. Recent theoretical studies have opened a new avenue to enhance their quantum-limited sensitivity by using active parity-time-symmetric and phase-insensitive quantum amplification. These systems can enhance the signal response without introducing excess noise in the ideal case. However, such active sys… ▽ More The sensitivity of laser interferometers is fundamentally limited by the quantum nature of light. Recent theoretical studies have opened a new avenue to enhance their quantum-limited sensitivity by using active parity-time-symmetric and phase-insensitive quantum amplification. These systems can enhance the signal response without introducing excess noise in the ideal case. However, such active systems must be causal, stable, and carefully tuned to be practical and applicable to precision measurements. In this paper, we show that phase-insensitive amplification in laser interferometers can be implemented in a tabletop experiment. The layout consists of two coupled cavities and an active medium comprised of a silicon nitride membrane and an auxiliary pump field. Our design relies on existing membrane and cryogenic technology and can demonstrate three distinct features: (i) the self-stabilized dynamics of the optical system, (ii) quantum enhancement of its sensitivity in the presence of the amplifier, and (iii) optical control of the amplifier gain. These features are needed to enhance the sensitivity of future interferometric gravitational-wave and axion detectors. △ Less

Submitted 10 October, 2022; originally announced October 2022.

Comments: 8 pages, 5 figures

The Development of Spatial Attention U-Net for The Recovery of Ionospheric Measurements and The Extraction of Ionospheric Parameters

Authors: Guan-Han Huang, Alexei V. Dmitriev, Chia-Hsien Lin, Yu-Chi Chang, Mon-Chai Hsieh, Enkhtuya Tsogtbaatar, Merlin M. Mendoza, Hao-Wei Hsu, Yu-Chiang Lin, Lung-Chih Tsai, Yung-Hui Li

Abstract: We train a deep learning artificial neural network model, Spatial Attention U-Net to recover useful ionospheric signals from noisy ionogram data measured by Hualien's Vertical Incidence Pulsed Ionospheric Radar. Our results show that the model can well identify F2 layer ordinary and extraordinary modes (F2o, F2x) and the combined signals of the E layer (ordinary and extraordinary modes and sporadi… ▽ More We train a deep learning artificial neural network model, Spatial Attention U-Net to recover useful ionospheric signals from noisy ionogram data measured by Hualien's Vertical Incidence Pulsed Ionospheric Radar. Our results show that the model can well identify F2 layer ordinary and extraordinary modes (F2o, F2x) and the combined signals of the E layer (ordinary and extraordinary modes and sporadic Es). The model is also capable of identifying some signals that were not labeled. The performance of the model can be significantly degraded by insufficient number of samples in the data set. From the recovered signals, we determine the critical frequencies of F2o and F2x and the intersection frequency between the two signals. The difference between the two critical frequencies is peaking at 0.63 MHz, with the uncertainty being 0.18 MHz. △ Less

Submitted 15 September, 2022; originally announced September 2022.

Comments: 17 pages, 7 figures, 3 tables

Journal ref: Radio Science 57 (2022) e2022RS007471

Nanoscale engineering of optical strong coupling inside metals

Authors: Artyom Assadillayev, Ihar Faniayeu, Alexandre Dmitriev, Søren Raza

Abstract: Optical polaritons appear when a material excitation strongly couples to the optical mode. Such strong coupling between molecular transitions and optical cavities results in far-reaching opportunities in modifying fundamental properties of chemical matter. More recently an exciting prospect of cavity-free polaritons has emerged by matter sustaining the optical mode with its geometry. Here we show… ▽ More Optical polaritons appear when a material excitation strongly couples to the optical mode. Such strong coupling between molecular transitions and optical cavities results in far-reaching opportunities in modifying fundamental properties of chemical matter. More recently an exciting prospect of cavity-free polaritons has emerged by matter sustaining the optical mode with its geometry. Here we show how strong coupling of the interband transition and surface plasmons can be engineered in nickel at the nanoscale to realize cavity-free optical polaritons inside metals. Using electron energy-loss spectroscopy, we demonstrate that in thin films and nanoantennas the propagation and radiation losses result in a broadening of the plasmon linewidth and a transition from strong to weak coupling. Further, higher-order plasmon resonances couple to the interband transition, and the multipolar coupled states acquire the field profile of the plasmon. Our results provide a fundamental understanding of plasmon-interband coupling in metals and establish the base for the design of unforeseen photocatalytic and magneto-optical nanosystems. △ Less

Submitted 13 July, 2022; originally announced July 2022.

Comments: 15 pages, 5 figures

Hybrid Dielectric-Plasmonic Nanoantenna with Multiresonances for Subwavelength Photon Sources

Authors: Pavel A. Dmitriev, Emmanuel Lassalle, Lu Ding, Zhenying Pan, Darren C. J. Neo, Vytautas Valuckas, Ramón Paniagua-Dominguez, Joel K. W. Yang, Hilmi Volkan Demir, Arseniy I. Kuznetsov

Abstract: The enhancement of the photoluminescence of quantum dots induced by an optical nanoantenna has been studied considerably, but there is still significant interest in optimizing and miniaturizing such structures, especially when accompanied by an experimental demonstration. Most of the realizations use plasmonic platforms, and some also use all-dielectric nanoantennas, but hybrid dielectric-plasmoni… ▽ More The enhancement of the photoluminescence of quantum dots induced by an optical nanoantenna has been studied considerably, but there is still significant interest in optimizing and miniaturizing such structures, especially when accompanied by an experimental demonstration. Most of the realizations use plasmonic platforms, and some also use all-dielectric nanoantennas, but hybrid dielectric-plasmonic (subwavelength) nanostructures have been very little explored. In this paper, we propose and demonstrate single subwavelength hybrid dielectric-plasmonic optical nanoantennas coupled to localized quantum dot emitters that constitute efficient and bright unidirectional photon sources under optical pumping. To achieve this, we devised a silicon nanoring sitting on a gold mirror with a 10 nm gap in-between, where an assembly of colloidal quantum dots is embedded. Such a structure supports both (radiative) antenna mode and (nonradiative) gap mode resonances, which we exploit for the dual purpose of out-coupling the light emitted by the quantum dots into the far-field with out-of-plane directivity, and for enhancing the excitation of the dots by the optical pump. Moreover, almost independent control of the resonance spectral positions can be achieved by simple tuning of geometrical parameters such as the ring inner and outer diameters, allowing us to conveniently adjust these resonances with respect to the quantum dots emission and absorption wavelengths. Using the proposed architecture, we obtain experimentally average fluorescence enhancement factors up to $654\times$ folds mainly due to high radiative efficiencies, and associated with a directional emission of the photoluminescence into a cone of $\pm 17\degree$ in the direction normal to the sample plane. We believe the solution presented here to be viable and relevant for the next generation of light-emitting devices. △ Less

Submitted 28 February, 2023; v1 submitted 27 June, 2022; originally announced June 2022.

Comments: 39 pages, 4 figures

Ultrafast collapse of molecular polaritons in photoswitch-nanoantennas at room temperature

Authors: Joel Kuttruff, Marco Romanelli, Esteban Pedrueza-Villalmanzo, Jonas Allerbeck, Jacopo Fregoni, Valeria Saavedra-Becerril, Joakim Andréasson, Daniele Brida, Alexandre Dmitriev, Stefano Corni, Nicolò Maccaferri

Abstract: Molecular polaritons are hybrid light-matter states that emerge when a molecular transition strongly interacts with photons in a resonator. At optical frequencies, this interaction unlocks a way to explore and control new chemical phenomena at the nanoscale. Achieving such a control at ultrafast timescales, however, is an outstanding challenge, as it requires a deep understanding of the dynamics o… ▽ More Molecular polaritons are hybrid light-matter states that emerge when a molecular transition strongly interacts with photons in a resonator. At optical frequencies, this interaction unlocks a way to explore and control new chemical phenomena at the nanoscale. Achieving such a control at ultrafast timescales, however, is an outstanding challenge, as it requires a deep understanding of the dynamics of the collectively coupled molecular excitation and the nanoconfined electromagnetic fields. Here, we investigate the dynamics of collective polariton states, realized by coupling molecular photoswitches to optically anisotropic plasmonic nanoantennas. Pump-probe experiments reveal an ultrafast collapse of polaritons to a single-molecule transition triggered by femtosecond-pulse excitation at room-temperature. Through a synergistic combination of experiments and quantum mechanical modelling, we show that the response of the system is governed by intramolecular dynamics, occurring one order of magnitude faster with respect to the unperturbed excited molecule relaxation to the ground state. △ Less

Submitted 12 May, 2022; originally announced May 2022.

Status and initial physics performance studies of the MPD experiment at NICA

Authors: MPD Collaboration, V. Abgaryan, R. Acevedo Kado, S. V. Afanasyev, G. N. Agakishiev, E. Alpatov, G. Altsybeev, M. Alvarado Hernández, S. V. Andreeva, T. V. Andreeva, E. V. Andronov, N. V. Anfimov, A. A. Aparin, V. I. Astakhov, E. Atkin, T. Aushev, G. S. Averichev, A. V. Averyanov, A. Ayala, V. A. Babkin, T. Babutsidze, I. A. Balashov, A. Bancer, M. Yu. Barabanov, D. A. Baranov , et al. (454 additional authors not shown)

Abstract: The Nuclotron-base Ion Collider fAcility (NICA) is under construction at the Joint Institute for Nuclear Research (JINR), with commissioning of the facility expected in late 2022. The Multi-Purpose Detector (MPD) has been designed to operate at NICA and its components are currently in production. The detector is expected to be ready for data taking with the first beams from NICA. This document pro… ▽ More The Nuclotron-base Ion Collider fAcility (NICA) is under construction at the Joint Institute for Nuclear Research (JINR), with commissioning of the facility expected in late 2022. The Multi-Purpose Detector (MPD) has been designed to operate at NICA and its components are currently in production. The detector is expected to be ready for data taking with the first beams from NICA. This document provides an overview of the landscape of the investigation of the QCD phase diagram in the region of maximum baryonic density, where NICA and MPD will be able to provide significant and unique input. It also provides a detailed description of the MPD set-up, including its various subsystems as well as its support and computing infrastructures. Selected performance studies for particular physics measurements at MPD are presented and discussed in the context of existing data and theoretical expectations. △ Less

Submitted 16 February, 2022; originally announced February 2022.

Comments: 53 pages, 68 figures, submitted as a Review article to EPJA

Journal ref: Eur. Phys. J. A 58, 140 (2022)

Radiofrequency response of the optically detected level anti-crossing signal in NV color centers in diamond in zero and weak magnetic fields

Authors: Alexander K. Dmitriev, Anton K. Vershovskii

Abstract: The response of the level anti-crossing signal to a quasi-resonant radio-frequency field, which appears in a zero magnetic field at NV color centers in diamond, is investigated. It is shown that the complex structure of this response can be explained by the Autler-Townes splitting. The possibility of controlling the parameters of the level anti-crossing signal is considered. It is shown that the s… ▽ More The response of the level anti-crossing signal to a quasi-resonant radio-frequency field, which appears in a zero magnetic field at NV color centers in diamond, is investigated. It is shown that the complex structure of this response can be explained by the Autler-Townes splitting. The possibility of controlling the parameters of the level anti-crossing signal is considered. It is shown that the slope of the central resonance recorded in this structure upon low-frequency modulation of the external magnetic field can be 2.3 times higher than the slope of the resonance recorded in the absence of an RF field. Conclusions are drawn about the nature of the level anti-crossing effect arising in zero field in NV color centers in diamond. △ Less

Submitted 19 January, 2022; v1 submitted 18 January, 2022; originally announced January 2022.

Electric dipole in a magnetic field: some aspects of the problem

Authors: A. P. Dmitriev

Abstract: In the paper some regimes of motion of an electric dipole placed in a uniform magnetic field are considered. The motion of both three-dimensional and two-dimensional dipole in the plane perpendicular to the magnetic field is studied. In the case of a two-dimensional dipole is discussed, in particular, the regime of chaotic dipole motion, which arises when, along with the magnetic field, there is a… ▽ More In the paper some regimes of motion of an electric dipole placed in a uniform magnetic field are considered. The motion of both three-dimensional and two-dimensional dipole in the plane perpendicular to the magnetic field is studied. In the case of a two-dimensional dipole is discussed, in particular, the regime of chaotic dipole motion, which arises when, along with the magnetic field, there is an electric field rotating in the plane of motion. The motion of a three-dimensional dipole is discussed in cases that allow for analytical consideration. Finally, the same examples are used to discuss the quantum-mechanical approach to the problem. △ Less

Submitted 8 December, 2021; originally announced December 2021.

Comments: 13 pages, 3 figures

Effects of photon statistics in wave mixing on a single qubit

Authors: W. V. Pogosov, A. Yu. Dmitriev, O. V. Astafiev

Abstract: We theoretically consider wave mixing under the irradiation of a single qubit by two photon fields. The first signal is a classical monochromatic drive, while the second one is a nonclassical light. Particularly, we address two examples of a nonclassical light: (i) a broadband squeezed light and (ii) a periodically excited quantum superposition of Fock states with 0 and 1 photons. The mixing of cl… ▽ More We theoretically consider wave mixing under the irradiation of a single qubit by two photon fields. The first signal is a classical monochromatic drive, while the second one is a nonclassical light. Particularly, we address two examples of a nonclassical light: (i) a broadband squeezed light and (ii) a periodically excited quantum superposition of Fock states with 0 and 1 photons. The mixing of classical and nonclassical photon fields gives rise to side peaks due to the elastic multiphoton scattering. We show that side peaks structure is distinct from the situation when two classical fields are mixed. The most striking feature is that some peaks are absent. The analysis of peak amplitudes can be used to probe photon statistics in the nonclassical mode. △ Less

Submitted 22 July, 2021; originally announced July 2021.

Comments: 14 pages, accepted for publication in Phys. Rev. A

Journal ref: Phys. Rev. A 104, 023703 (2021)

Magnetic Circular Dichroism in Hyperbolic Metamaterial Nanoparticles

Authors: Joel Kuttruff, Alessio Gabbani, Gaia Petrucci, Yingqi Zhao, Marzia Iarossi, Esteban Pedrueza-Villalmanzo, Alexandre Dmitriev, Antonietta Parracino, Giuseppe Strangi, Francesco De Angelis, Daniele Brida, Francesco Pineider, Nicolò Maccaferri

Abstract: The optical properties of some nanomaterials can be controlled by an external magnetic field, providing active functionalities for a wide range of applications, from single-molecule sensing to nanoscale nonreciprocal optical isolation. Materials with broadband tunable magneto-optical response are therefore highly desired for various components in next-generation integrated photonic nanodevices. Co… ▽ More The optical properties of some nanomaterials can be controlled by an external magnetic field, providing active functionalities for a wide range of applications, from single-molecule sensing to nanoscale nonreciprocal optical isolation. Materials with broadband tunable magneto-optical response are therefore highly desired for various components in next-generation integrated photonic nanodevices. Concurrently, hyperbolic metamaterials received a lot of attention in the past decade since they exhibit unusual properties that are rarely observed in nature and provide an ideal platform to control the optical response at the nanoscale via careful design of the effective permittivity tensor, surpassing the possibilities of conventional systems. Here, we experimentally study magnetic circular dichroism in a metasurface made of type-II hyperbolic nanoparticles on a transparent substrate. Numerical simulations confirm the experimental findings, and an analytical model is established to explain the physical origin of the observed magneto-optical effects, which can be described in terms of the coupling of fundamental electric and magnetic dipole modes with an external magnetic field. Our system paves the way for the development of nanophotonic active devices combining the benefits of sub-wavelength light manipulation in hyperbolic metamaterials supporting a large density of optical states with the ability to freely tune the magneto-optical response via control over the anisotropic permittivity of the system. △ Less

Submitted 25 March, 2021; originally announced March 2021.

Macroscopic Magneto-Chiroptical Metasurfaces

Authors: Gaia Petrucci, Alessio Gabbani, Esteban Pedrueza-Villalmanzo, Giuseppe Cucinotta, Matteo Atzori, Alexandre Dmitriev, Francesco Pineider

Abstract: Nanophotonic chiral antennas exhibit orders of magnitude higher circular dichroism (CD) compared to molecular systems. Merging magnetism and structural chirality at the nanometric level allows for the efficient magnetic control of the dichroic response, bringing exciting new prospects to active nanophotonic devices and magnetochirality. Here we devise macroscale enantiomeric magnetophotonic metasu… ▽ More Nanophotonic chiral antennas exhibit orders of magnitude higher circular dichroism (CD) compared to molecular systems. Merging magnetism and structural chirality at the nanometric level allows for the efficient magnetic control of the dichroic response, bringing exciting new prospects to active nanophotonic devices and magnetochirality. Here we devise macroscale enantiomeric magnetophotonic metasurfaces of plasmon and ferromagnetic spiral antennas. Mixed 2D- and 3D- chiral nanoantennas induce large CD response, where we identify reciprocal and non-reciprocal contributions. The simultaneous chiroptical and magneto-optical response in a wide spectral range with these metasurfaces delivers an attractive platform for the study of magnetochirality at the nanoscale. Exploring further this type of magnetophotonic metasurfaces allows the realization of high-sensitivity chiral sensors and prompts the design of novel macroscopic optical devices operating with polarized light. △ Less

Submitted 22 March, 2021; originally announced March 2021.

Comments: Main text: 5 pages, 3 figures. Supporting information: 6 pages, 6 figures

Higher-order topological states mediated by long-range coupling in $D_4$-symmetric lattices

Authors: Nikita A. Olekhno, Alina D. Rozenblit, Valerii I. Kachin, Alexey A. Dmitriev, Oleg I. Burmistrov, Pavel S. Seregin, Dmitry V. Zhirihin, Maxim A. Gorlach

Abstract: Topological physics opens a door towards flexible routing and resilient localization of waves of various nature. Recently proposed higher-order topological insulators provide advanced control over wave localization in the structures of different dimensionality. In many cases, the formation of such higher-order topological phases is governed by the lattice symmetries, with kagome and breathing hone… ▽ More Topological physics opens a door towards flexible routing and resilient localization of waves of various nature. Recently proposed higher-order topological insulators provide advanced control over wave localization in the structures of different dimensionality. In many cases, the formation of such higher-order topological phases is governed by the lattice symmetries, with kagome and breathing honeycomb lattices being prominent examples. Here, we design and experimentally realize the resonant electric circuit with $D_4$ symmetry and additional next-nearest-neighbor couplings. As we prove, a coupling of the distant neighbors gives rise to an in-gap corner state. Retrieving the associated invariant directly from the experiment, we demonstrate the topological nature of the designed system, revealing the role of long-range interactions in the formation of topological phases. Our results thus highlight the distinctions between tight-binding systems and their photonic counterparts with long-range couplings. △ Less

Submitted 16 March, 2021; originally announced March 2021.

Comments: 6 pages, 3 figures+Supplementary Materials

Journal ref: Phys. Rev. B 105, L081107 (2022)

Ultrafast demagnetization in a ferrimagnet under electromagnetic field funneling

Authors: Kshiti Mishra, Agne Ciuciulkaite, Mario Zapata-Herrera, Paolo Vavassori, Vassilios Kapaklis, Theo Rasing, Alexandre Dmitriev, Alexey Kimel, Andrei Kirilyuk

Abstract: The quest to improve density, speed and energy efficiency of magnetic memory storage has led to exploration of new ways of optically manipulating magnetism at the ultrafast time scale, in particular in ferrimagnetic alloys. While all-optical magnetization switching is well-established on the femtosecond timescale, lateral nanoscale confinement and thus potential significant reduction of the size o… ▽ More The quest to improve density, speed and energy efficiency of magnetic memory storage has led to exploration of new ways of optically manipulating magnetism at the ultrafast time scale, in particular in ferrimagnetic alloys. While all-optical magnetization switching is well-established on the femtosecond timescale, lateral nanoscale confinement and thus potential significant reduction of the size of the magnetic element remains an outstanding challenge. Here we employ resonant electromagnetic energy-funneling plasmon nanoantennas to influence the demagnetization dynamics of a ferrimagnetic TbCo alloy thin film. We demonstrate how Ag nanoring-shaped antennas under resonant optical femtosecond pumping reduce the overall magneto-optical response due to demagnetization in the underlying films up to three times compared to non-resonant illumination. We attribute such substantial reduction to the nanoscale confinement of the demagnetization process. This is qualitatively supported by the electromagnetic simulations that strongly evidence the optical energy-funneling to the nanoscale from the nanoantennas into the ferrimagnetic film. This is the first and defining step for reaching deterministic ultrafast all-optical magnetization switching at the nanoscale in such systems, opening a route to develop nanoscale ultrafast magneto-optics. △ Less

Submitted 9 March, 2021; originally announced March 2021.

Direction-sensitive magnetophotonic surface crystal

Authors: Richard M. Rowan-Robinson, Jérome Hurst, Agne Ciuciulkaite, Ioan-Augustin Chioar, Merlin Pohlit, Mario Zapata, Paolo Vavassori, Alexandre Dmitriev, Peter M. Oppeneer, Vassilios Kapaklis

Abstract: Nanometer-thin rare-earth-transition metal (RE-TM) alloys with precisely controlled compositions and out-of-plane magnetic anisotropy are currently in the focus for ultrafast magnetophotonic applications. However, achieving lateral nanoscale dimensions, crucial for potential device downscaling, while maintaining designable optomagnetic functionality and out-of-plane magnetic anisotropy is extremel… ▽ More Nanometer-thin rare-earth-transition metal (RE-TM) alloys with precisely controlled compositions and out-of-plane magnetic anisotropy are currently in the focus for ultrafast magnetophotonic applications. However, achieving lateral nanoscale dimensions, crucial for potential device downscaling, while maintaining designable optomagnetic functionality and out-of-plane magnetic anisotropy is extremely challenging. Here we integrate nanosized Tb$_{18}$Co$_{82}$ ferrimagnetic alloys, having strong out-of-plane magnetic anisotropy, within a gold plasmonic nanoantenna array to design micrometer-scale a magnetophotonic crystal that exhibit abrupt and narrow magneto-optical spectral features that are both magnetic field and light incidence direction controlled. The narrow Fano-type resonance arises through the interference of the individual nanoantenna's surface plasmons and a Rayleigh anomaly of the whole nanoantenna array, in both optical and magneto-optical spectra, which we demonstrate and explain using Maxwell-theory simulations. This robust magnetophotonic crystal opens the way for conceptually new high-resolution light incidence direction sensors, as well as for building blocks for plasmon-assisted all-optical magnetization switching in ferrimagnetic RE-TM alloys. △ Less

Submitted 18 May, 2021; v1 submitted 29 May, 2020; originally announced May 2020.

Comments: 13 pages, 4 figures

Journal ref: Advanced Photonics Research 2, 2100119 (2021)

Negative thermal expansion induced suppression of wear in dry sliding friction

Authors: Aleksandr S. Grigoriev, Evgeny V. Shilko, Andrey I. Dmitriev, Sergey Yu. Tarasov

Abstract: Surface temperature is among crucial factors, which control wear during sliding dry contact. Using computer modeling, we study the possibility to achieve close to zero rate of surface wear during sliding friction of the special type of materials, which possess negative thermal expansion. The numerical simulations reveal two wear regimes for negative thermal expansion materials as dependent on the… ▽ More Surface temperature is among crucial factors, which control wear during sliding dry contact. Using computer modeling, we study the possibility to achieve close to zero rate of surface wear during sliding friction of the special type of materials, which possess negative thermal expansion. The numerical simulations reveal two wear regimes for negative thermal expansion materials as dependent on the applied normal stress level. When the applied stress is lower than that of a critical level, a steady almost zero wear rate and nanorough surface are achieved during friction. Otherwise, wear rate is of the same order of magnitude as for positive thermal expansion materials. The critical stress value is analyzed as depending on the material's mechanical, thermophysical, and surface roughness characteristics. △ Less

Submitted 14 May, 2020; originally announced May 2020.

Comments: 5 pages, 4 figures

Journal ref: Phys. Rev. E 102, 042801 (2020)

Light-dressing of a diatomic superconducting artificial molecule

Authors: G. P. Fedorov, V. B. Yursa, A. E. Efimov, K. I. Shiianov, A. Yu. Dmitriev, I. A. Rodionov, A. A. Dobronosova, D. O. Moskalev, A. A. Pishchimova, E. I. Malevannaya, O. V. Astafiev

Abstract: In this work, we irradiate a superconducting artificial molecule composed of two coupled tunable transmons with microwave light while monitoring its state via joint dispersive readout. Performing high-power spectroscopy, we observe and identify a variety of single- and multiphoton transitions. We also find that at certain fluxes, the measured spectrum of the system deviates significantly from the… ▽ More In this work, we irradiate a superconducting artificial molecule composed of two coupled tunable transmons with microwave light while monitoring its state via joint dispersive readout. Performing high-power spectroscopy, we observe and identify a variety of single- and multiphoton transitions. We also find that at certain fluxes, the measured spectrum of the system deviates significantly from the solution of the stationary Schrödinger equation with no driving. We reproduce these unusual spectral features by solving numerically the full master equation for a steady-state and attribute them to an Autler-Townes-like effect in which a single tone is simultaneously dressing the system and probing the transitions between new eigenstates. We show that it is possible to find analytically the exact frequencies at which the satellite spectral lines appear by solving self-consistent equations in the rotating frame. Our approach agrees well with both the experiment and the numerical simulation. △ Less

Submitted 5 June, 2020; v1 submitted 27 January, 2020; originally announced January 2020.

Comments: 18 pages, 9 figures

Journal ref: Phys. Rev. A 102, 013707 (2020)

Perspective: Plasmon antennas for nanoscale chiral chemistry

Authors: Esteban Pedrueza-Villalmanzo, Francesco Pineider, Alexandre Dmitriev

Abstract: Plasmon nanoantennas are extensively used with molecular systems for the chemical and biological ultra-sensing, for boosting the molecular emissive and energy transfer properties, for the nanoscale catalysis, and for building advanced hybrid nanoarchitectures. In this Perspective we focus on the latest developments of using plasmon nanoantennas for the nanoscale chiral chemistry and for advancing… ▽ More Plasmon nanoantennas are extensively used with molecular systems for the chemical and biological ultra-sensing, for boosting the molecular emissive and energy transfer properties, for the nanoscale catalysis, and for building advanced hybrid nanoarchitectures. In this Perspective we focus on the latest developments of using plasmon nanoantennas for the nanoscale chiral chemistry and for advancing the molecular magnetism. We overview the decisive role nanoplasmonics and nano-optics can play in achieving the chirally-selective molecular synthesis and separation, and in the way such processes might be precisely controlled by potentially merging chirality and magnetism at the molecular level. We give our view on how these insights might lead to the emergence of exciting new fundamental concepts in the nanoscale materials science. △ Less

Submitted 14 October, 2019; originally announced October 2019.

Strong optical coupling combines isolated scatterers into dimer

Authors: Alexey A. Dmitriev, Mikhail V. Rybin

Abstract: We analyze the transition between different coupling regimes of two dielectric rods, which occurs at a critical distance between them. The hallmark of strong coupling regime is the peak splitting effect observed in spectra. Here we comprehensively evaluate the critical distance as a function of the rod permittivity using a number of different approaches. The scattering spectra of the two rods in d… ▽ More We analyze the transition between different coupling regimes of two dielectric rods, which occurs at a critical distance between them. The hallmark of strong coupling regime is the peak splitting effect observed in spectra. Here we comprehensively evaluate the critical distance as a function of the rod permittivity using a number of different approaches. The scattering spectra of the two rods in dependence on the distance demonstrate the weak to strong coupling transition. We start the analysis by introducing a region of a tidal energy flux around a single isolated rod (the region is related to the near field) and demonstrate that its effective radius corresponds to the critical distance obtained from the scattering spectra. Next, we study the eigenfrequencies of the dimer as functions of distance by 'diagonalizing' the coupled multipole matrix. In order to find an analytical formula for the critical distance, we consider the problem under several approximations, which yield similar results. △ Less

Submitted 4 June, 2019; originally announced June 2019.

Comments: 10 pages, 6 figures

Journal ref: Phys. Rev. A 99, 063837 (2019)

Enhancement of laser-driven ion acceleration in non-periodic nanostructured targets

Authors: I. Thiele, J. Ferri, E. Siminos, L. Gremillet, E. Smetanina, A. Dmitriev, G. Cantono, C. -G. Wahlström, T. Fülöp

Abstract: Using particle-in-cell simulations, we demonstrate an improvement of the target normal sheath acceleration (TNSA) of protons in non-periodically nanostructured targets with micron-scale thickness. Compared to standard flat foils, an increase in the proton cutoff energy by up to a factor of two is observed in foils coated with nanocones or perforated with nanoholes. The latter nano-perforated foils… ▽ More Using particle-in-cell simulations, we demonstrate an improvement of the target normal sheath acceleration (TNSA) of protons in non-periodically nanostructured targets with micron-scale thickness. Compared to standard flat foils, an increase in the proton cutoff energy by up to a factor of two is observed in foils coated with nanocones or perforated with nanoholes. The latter nano-perforated foils yield the highest enhancement, which we show to be robust over a broad range of foil thicknesses and hole diameters. The improvement of TNSA performance results from more efficient hot-electron generation, caused by a more complex laser-electron interaction geometry and increased effective interaction area and duration. We show that TNSA is optimized for a nanohole distribution of relatively low areal density and that is not required to be periodic, thus relaxing the manufacturing constraints. △ Less

Submitted 16 July, 2019; v1 submitted 27 May, 2019; originally announced May 2019.

Comments: 11 pages, 8 figures

Nanoscale magnetophotonics

Authors: Nicolò Maccaferri, Irina Zubritskaya, Ilya Razdolski, Ioan-Augustin Chioar, Vladimir Belotelov, Vassilios Kapaklis, Peter M. Oppeneer, Alexandre Dmitriev

Abstract: This Perspective surveys the state-of-the-art and future prospects of science and technology employing the nanoconfined light (nanophotonics and nanoplasmonics) in combination with magnetism. We denote this field broadly as nanoscale magnetophotonics. We include a general introduction to the field and describe the emerging magneto-optical effects in magnetoplasmonic and magnetophotonic nanostructu… ▽ More This Perspective surveys the state-of-the-art and future prospects of science and technology employing the nanoconfined light (nanophotonics and nanoplasmonics) in combination with magnetism. We denote this field broadly as nanoscale magnetophotonics. We include a general introduction to the field and describe the emerging magneto-optical effects in magnetoplasmonic and magnetophotonic nanostructures supporting localized and propagating plasmons. Special attention is given to magnetoplasmonic crystals with transverse magnetization and the associated nanophotonic non-reciprocal effects, and to magneto-optical effects in periodic arrays of nanostructures. We give also an overview of the applications of these systems in biological and chemical sensing, as well as in light polarization and phase control. We further review the area of nonlinear magnetophotonics, the semiconductor spin-plasmonics, and the general principles and applications of opto-magnetism and nano-optical ultrafast control of magnetism and spintronics. △ Less

Submitted 18 February, 2020; v1 submitted 26 April, 2019; originally announced April 2019.

Counterflows in viscous electron-hole fluid

Authors: P. S. Alekseev, A. P. Dmitriev, I. V. Gornyi, V. Yu. Kachorovskii, B. N. Narozhny, M. Titov

Abstract: In ultra-pure conductors, collective motion of charge carriers at relatively high temperatures may become hydrodynamic such that electronic transport may be described similarly to a viscous flow. In confined geometries (e.g., in ultra-high quality nanostructures), the resulting flow is Poiseuille-like. When subjected to a strong external magnetic field, the electric current in semimetals is pushed… ▽ More In ultra-pure conductors, collective motion of charge carriers at relatively high temperatures may become hydrodynamic such that electronic transport may be described similarly to a viscous flow. In confined geometries (e.g., in ultra-high quality nanostructures), the resulting flow is Poiseuille-like. When subjected to a strong external magnetic field, the electric current in semimetals is pushed out of the bulk of the sample towards the edges. Moreover, we show that the interplay between viscosity and fast recombination leads to the appearance of counterflows. The edge currents possess a non-trivial spatial profile and consist of two stripe-like regions: the outer stripe carrying most of the current in the direction of the external electric field and the inner stripe with the counterflow. △ Less

Submitted 25 May, 2018; originally announced May 2018.

Comments: 10 pages, 5 figures

Journal ref: Phys. Rev. B 98, 125111 (2018)

Effective surface conductivity of plasmonic metasurfaces: from far-field characterization to surface wave analysis

Authors: Oleh Y. Yermakov, Dmitry V. Permyakov, Filipp V. Porubaev, Pavel A. Dmitriev, Dmitry A. Baranov, Anton K. Samusev, Ivan V. Iorsh, Radu Malureanu, Andrey A. Bogdanov, Andrei V. Lavrinenko

Abstract: Metasurfaces offer great potential to control near- and far-fields through engineering of optical properties of elementary cells or meta-atoms. Such perspective opens a route to efficient manipulation of the optical signals both at nanoscale and in photonics applications. In this paper we show that by using an effective surface conductivity tensor it is possible to unambigiously describe optical p… ▽ More Metasurfaces offer great potential to control near- and far-fields through engineering of optical properties of elementary cells or meta-atoms. Such perspective opens a route to efficient manipulation of the optical signals both at nanoscale and in photonics applications. In this paper we show that by using an effective surface conductivity tensor it is possible to unambigiously describe optical properties of an anisotropic metasurface in the far- and near-field regimes. We begin with retrieving the effective surface conductivity tensor from the comparative analysis of experimental and numerical reflectance spectra of a metasurface composed of elliptical gold nanoparticles. Afterwards restored conductivities are validated in the crosscheck versus semianalytic parameters obtained with the discrete dipole model with and without dipoles interaction contribution. The obtained effective parameters are further used for the dispersion analysis of surface plasmons localized at the metasurface. The effective medium model predicts existence of both TE- and TM-polarized plasmons in a wide range of optical frequencies and describes peculiarities of their dispersion, in particularly, topological transition from the elliptical to hyperbolic regime with eligible accuracy. The analysis in question offers a simple practical way to describe properties of metasurfaces including ones in the near-field zone by extracting effective parameters from the convenient far-field characterisation. △ Less

Submitted 18 December, 2017; originally announced December 2017.

Comments: 29 pages, 9 figures

Nonmonotonic magnetoresistance of a two-dimensional viscous electron-hole fluid in a confined geometry

Authors: P. S. Alekseev, A. P. Dmitriev, I. V. Gornyi, V. Yu. Kachorovskii, B. N. Narozhny, M. Titov

Abstract: Ultra-pure conductors may exhibit hydrodynamic transport where the collective motion of charge carriers resembles the flow of a viscous fluid. In a confined geometry (e.g., in ultra-high quality nanostructures) the electronic fluid assumes a Poiseuille-like flow. Applying an external magnetic field tends to diminish viscous effects leading to large negative magnetoresistance. In two-component syst… ▽ More Ultra-pure conductors may exhibit hydrodynamic transport where the collective motion of charge carriers resembles the flow of a viscous fluid. In a confined geometry (e.g., in ultra-high quality nanostructures) the electronic fluid assumes a Poiseuille-like flow. Applying an external magnetic field tends to diminish viscous effects leading to large negative magnetoresistance. In two-component systems near charge neutrality the hydrodynamic flow of charge carriers is strongly affected by the mutual friction between the two constituents. At low fields, the magnetoresistance is negative, however at high fields the interplay between electron-hole scattering, recombination, and viscosity results in a dramatic change of the flow profile: the magnetoresistance changes its sign and eventually becomes linear in very high fields. This novel non-monotonic magnetoresistance can be used as a fingerprint to detect viscous flow in two-component conducting systems. △ Less

Submitted 9 November, 2017; originally announced November 2017.

Comments: 10 pages, 8 figures

Journal ref: Phys. Rev. B 97, 085109 (2018)

Localization of light in an optical microcapillary introduced by a droplet

Authors: Tabassom Hamidfar, Kirill V. Tokmakov, Brian J. Mangan, Robert S. Windeler, Artemiy V. Dmitriev, Dashiell L. P. Vitullo, Pablo Bianucci, Michael Sumetsky

Abstract: Sensing with optical whispering gallery modes (WGMs) is a rapidly developing detection method in modern microfluidics research. This method explores the perturbations of spectra of WGMs propagating along the wall of an optical microcapillary to characterize the liquid medium inside it. Here we show that WGMs in a silica microcapillary can be fully localized (rather than perturbed) by evanescent co… ▽ More Sensing with optical whispering gallery modes (WGMs) is a rapidly developing detection method in modern microfluidics research. This method explores the perturbations of spectra of WGMs propagating along the wall of an optical microcapillary to characterize the liquid medium inside it. Here we show that WGMs in a silica microcapillary can be fully localized (rather than perturbed) by evanescent coupling to a water droplet and, thus, form a high quality-factor microresonator. The spectra of this resonator, measured with a microfiber translated along the capillary, present a hierarchy of resonances which allow us to determine the size of the droplet and variation of its length due to the evaporation. The resolution of our measurements of this variation equal to 4.5 nm is only limited by the resolution of the optical spectrum analyzer used. The discovered phenomenon of complete localization of light in liquid-filled optical microcapillaries suggests a new type of microfluidic photonic devices as well as an ultraprecise method for microfluidic characterization. △ Less

Submitted 29 October, 2017; originally announced October 2017.

Comments: 14 pages

Radio lighting based on dynamic chaos generators

Authors: Alexander Dmitriev, Elena Efremova, Mark Gerasimov, Vadim Itskov

Abstract: A problem of lighting objects and surfaces with artificial sources of noncoherent microwave radiation with the aim to observe them using radiometric equipment is considered. Transmitters based on dynamic chaos generators are used as sources of noncoherent wideband microwave radiation. An experimental sample of such a device, i.e., a radio lighting lamp based on a chaos microgenerator and its perfo… ▽ More A problem of lighting objects and surfaces with artificial sources of noncoherent microwave radiation with the aim to observe them using radiometric equipment is considered. Transmitters based on dynamic chaos generators are used as sources of noncoherent wideband microwave radiation. An experimental sample of such a device, i.e., a radio lighting lamp based on a chaos microgenerator and its performance are presented. △ Less

Submitted 19 September, 2016; originally announced September 2016.

Development of the MRPC for the TOF system of the MultiPurpose Detector

Authors: V. A. Babkin, S. N. Bazylev, I. S. Burdenyuk, M. G. Buryakov, A. V. Dmitriev, P. O. Dulov, V. M. Golovatyuk, S. P. Lobastov, M. M. Rumyantsev, A. V. Schipunov, A. V. Shutov, I. V. Slepnev, V. M. Slepnev, A. V. Terletskiy, S. V. Volgin

Abstract: The Multipurpose Detector (MPD) \cite{cite1.MPD_CDR} is designed to study of hot and dense baryonic matter in collisions of heavy ions over the atomic mass range 1--197 at the centre of mass energy up to $\sqrt{S_{NN}}$ = 11 GeV (for Au79+). The MPD experiment will be carried out at the JINR accelerator complex NICA \cite{cite2.NICA_CDR} which is under construction. The barrel part of the MPD cons… ▽ More The Multipurpose Detector (MPD) \cite{cite1.MPD_CDR} is designed to study of hot and dense baryonic matter in collisions of heavy ions over the atomic mass range 1--197 at the centre of mass energy up to $\sqrt{S_{NN}}$ = 11 GeV (for Au79+). The MPD experiment will be carried out at the JINR accelerator complex NICA \cite{cite2.NICA_CDR} which is under construction. The barrel part of the MPD consists of various detectors surrounding the interaction point. It includes a precise tracking system (time projection chamber (TPC) and silicon inner tracker (IT)) and high-performance particle identification system based on time-of-flight (TOF) and calorimeter (ECal). The triple-stack multigap resistive plate chamber is chosen as an active element of the TOF. It provides good time resolution and long term stability. This article presents parameters of the MRPC obtained using the deuteron beam of JINR accelerator Nuclotron. The time resolution is $\sim$40 ps with efficiency of 99\%. Rate capability studies resulted with a time resolution of 60 ps and efficiency higher than 90\% on the beam with particle flux densities up to 2 kHz/cm$^2$. △ Less

Submitted 6 June, 2016; originally announced June 2016.

Comments: 8 pages, 10 figures, Proceedings of the XIII Workshop on Resistive Plate Chambers and Related Detectors (RPC2016), February 22 - 26, 2016, Ghent, Belgium

Tunable photonic elements at the surface of an optical fiber with piezoelectric core

Authors: Artemiy V. Dmitriev, M. Sumetsky

Abstract: Tunable photonic elements at the surface of an optical fiber with piezoelectric core are proposed and analyzed theoretically. These elements are based on whispering gallery modes whose propagation along the fiber is fully controlled by nanoscale variation of the effective fiber radius, which can be tuned by means of a piezoelectric actuator embedded into the core. The developed theory allows one t… ▽ More Tunable photonic elements at the surface of an optical fiber with piezoelectric core are proposed and analyzed theoretically. These elements are based on whispering gallery modes whose propagation along the fiber is fully controlled by nanoscale variation of the effective fiber radius, which can be tuned by means of a piezoelectric actuator embedded into the core. The developed theory allows one to express the introduced effective radius variation through the shape of the actuator and the voltage applied to it. In particular, the design of a miniature tunable optical delay line and a miniature tunable dispersion compensator is presented. The potential application of the suggested model to the design of a miniature optical buffer is discussed. △ Less

Submitted 8 March, 2016; originally announced March 2016.

Comments: 5 pages, 3 figures