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Squeezing Classical Antiferromagnets into Quantum Spin Liquids via Global Cavity Fluctuations
Authors:
Charlie-Ray Mann,
Mark A. Oehlgrien,
Błażej Jaworowski,
Giuseppe Calajó,
Jamir Marino,
Kyung S. Choi,
Darrick E. Chang
Abstract:
Cavity quantum electrodynamics with atomic ensembles is typically associated with collective spin phenomena, such as superradiance and spin squeezing, in which the atoms evolve collectively as a macroscopic spin ($S\sim N/2$) on the Bloch sphere. Surprisingly, we show that the tendency toward a collective spin description need not imply collective spin phenomena; rather, it can be exploited to gen…
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Cavity quantum electrodynamics with atomic ensembles is typically associated with collective spin phenomena, such as superradiance and spin squeezing, in which the atoms evolve collectively as a macroscopic spin ($S\sim N/2$) on the Bloch sphere. Surprisingly, we show that the tendency toward a collective spin description need not imply collective spin phenomena; rather, it can be exploited to generate new forms of strongly correlated quantum matter. The key idea is to use uniform cavity-mediated interactions to energetically project the system into the total-spin singlet sector ($S=0$) - a highly entangled subspace where the physics is governed entirely by cavity fluctuations. Focusing on Rydberg atom arrays coupled to a single-mode cavity, we show that global cavity fluctuations can effectively squeeze classical antiferromagnets into quantum spin liquids, characterized by non-local entanglement, fractionalized excitations, and emergent gauge fields. This work suggests that cavity QED can be a surprising resource for inducing strongly correlated phenomena, which could be explored in the new generation of hybrid tweezer-cavity platforms.
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Submitted 5 December, 2025;
originally announced December 2025.
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Laughlin-like states of few atomic excitations in small subwavelength atom arrays
Authors:
Błażej Jaworowski,
Darrick E. Chang
Abstract:
Atom arrays with sub-wavelength lattice constant can exhibit fascinating optical properties. For example, the combination of $V$-type level structure and magnetic fields can yield topological band structures, making the neutral atomic excitations behave like charged particles in a magnetic field. Up to now, much of our understanding of these systems (and arrays in general) focuses on the single-ex…
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Atom arrays with sub-wavelength lattice constant can exhibit fascinating optical properties. For example, the combination of $V$-type level structure and magnetic fields can yield topological band structures, making the neutral atomic excitations behave like charged particles in a magnetic field. Up to now, much of our understanding of these systems (and arrays in general) focuses on the single-excitation regime. Here, we go beyond the single-excitation level to show that such systems can give rise to few-particle Laughlin-like states. In particular, we consider small honeycomb ``flakes,'' where the harmful divergences near the light cone can be smeared out by finite-size effects. By choosing an appropriate value of magnetic field we thereby obtain an energy spectrum and eigenstates resembling those of Landau levels. The native hard-core nature of atomic excitations then gives rise to multi-excitation Laughlin-like states. This phenomenon occurs not only in samples of tens of sites, but also in a minimal nanoring system of only six sites. Next, considering two-particle Laughlin-like states, we show that they can be driven by uniform light, and that correlations of the output light contain identifying fingerprints of these states. We believe that these results are a step towards new paradigms of engineering and understanding strongly-correlated many-body states in atom-light interfaces.
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Submitted 26 September, 2025; v1 submitted 23 April, 2025;
originally announced April 2025.
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Metalens formed by structured arrays of atomic emitters
Authors:
Francesco Andreoli,
Charlie-Ray Mann,
Alexander A. High,
Darrick E. Chang
Abstract:
Arrays of atomic emitters have proven to be a promising platform to manipulate and engineer optical properties, due to their efficient cooperative response to near-resonant light. Here, we theoretically investigate their use as an efficient metalens. We show that, by spatially tailoring the (sub-wavelength) lattice constants of three consecutive two-dimensional arrays of identical atomic emitters,…
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Arrays of atomic emitters have proven to be a promising platform to manipulate and engineer optical properties, due to their efficient cooperative response to near-resonant light. Here, we theoretically investigate their use as an efficient metalens. We show that, by spatially tailoring the (sub-wavelength) lattice constants of three consecutive two-dimensional arrays of identical atomic emitters, one can realize a large transmission coefficient with arbitrary position-dependent phase shift, whose robustness against losses is enhanced by the collective response. To characterize the efficiency of this atomic metalens, we perform large-scale numerical simulations involving a substantial number of atoms ($N\sim 5\times 10^5$) that is considerably larger than comparable works. Our results suggest that low-loss, robust optical devices with complex functionalities, ranging from metasurfaces to computer-generated holograms, could be potentially assembled from properly engineered arrays of atomic emitters.
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Submitted 29 October, 2024;
originally announced October 2024.
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The maximum refractive index of an atomic crystal $\unicode{x2013}$ from quantum optics to quantum chemistry
Authors:
Francesco Andreoli,
Bennet Windt,
Stefano Grava,
Gian Marcello Andolina,
Michael J. Gullans,
Alexander A. High,
Darrick E. Chang
Abstract:
All known optical materials have an index of refraction of order unity. Despite the tremendous implications that an ultrahigh index could have for optical technologies, little research has been done on why the refractive index of materials is universally small, and whether this observation is fundamental. Here, we investigate the index of an ordered arrangement of atoms, as a function of atomic de…
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All known optical materials have an index of refraction of order unity. Despite the tremendous implications that an ultrahigh index could have for optical technologies, little research has been done on why the refractive index of materials is universally small, and whether this observation is fundamental. Here, we investigate the index of an ordered arrangement of atoms, as a function of atomic density. At dilute densities, this problem falls into the realm of quantum optics, where atoms do not interact with one another except via the scattering of light. On the other hand, when the lattice constant becomes comparable to the Bohr radius, the electronic orbitals begin to overlap, giving rise to quantum chemistry. We present a minimal model that allows for a unifying theory of index spanning these two regimes. A key aspect is the treatment of multiple light scattering, which can be highly non-perturbative over a large density range, and which is the reason that conventional theories of the index break down. In the quantum optics regime, we show that ideal light-matter interactions can have a single-mode nature, allowing for a purely real refractive index that grows with density as $(N/V)^{1/3}$. At the onset of quantum chemistry, we show how two physical mechanisms (excited electron tunneling dynamics and the buildup of electronic density-density correlations) can open up inelastic or spatial multi-mode light scattering processes, which ultimately reduce the index back to order unity while introducing absorption. Around the onset of chemistry, our theory predicts that ultrahigh index ($n\sim 30$), low-loss materials could in principle be allowed by the laws of nature.
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Submitted 20 March, 2023;
originally announced March 2023.
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Nonlinear quantum logic with colliding graphene plasmons
Authors:
Giuseppe Calajò,
Philipp K. Jenke,
Lee A. Rozema,
Philip Walther,
Darrick E. Chang,
Joel D. Cox
Abstract:
Graphene has emerged as a promising platform to bring nonlinear quantum optics to the nanoscale, where a large intrinsic optical nonlinearity enables long-lived and actively tunable plasmon polaritons to strongly interact. Here we theoretically study the collision between two counter-propagating plasmons in a graphene nanoribbon, where transversal subwavelength confinement endows propagating plasm…
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Graphene has emerged as a promising platform to bring nonlinear quantum optics to the nanoscale, where a large intrinsic optical nonlinearity enables long-lived and actively tunable plasmon polaritons to strongly interact. Here we theoretically study the collision between two counter-propagating plasmons in a graphene nanoribbon, where transversal subwavelength confinement endows propagating plasmons with %large effective masses a flat band dispersion that enhances their interaction. This scenario presents interesting possibilities towards the implementation of multi-mode polaritonic gates that circumvent limitations imposed by the Shapiro no-go theorem for photonic gates in nonlinear optical fibers. As a paradigmatic example we demonstrate the feasibility of a high fidelity conditional Pi phase shift (CZ), where the gate performance is fundamentally limited only by the single-plasmon lifetime. These results open new exciting avenues towards quantum information and many-body applications with strongly-interacting polaritons.
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Submitted 18 March, 2023; v1 submitted 11 July, 2022;
originally announced July 2022.
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Emergence of solitons from many-body photon bound states in quantum nonlinear media
Authors:
Giuseppe Calajo,
Darrick E. Chang
Abstract:
Solitons are known to occur in the context of atom-light interaction via the well-known semi-classical phenomenon of self-induced transparency (SIT). Separately, in the regime where both light and atoms are fully treated quantum mechanically, quantum few-photon bound states are known to be a ubiquitous phenomenon that arises in different systems such as atoms coupled to chiral or bidirectional wav…
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Solitons are known to occur in the context of atom-light interaction via the well-known semi-classical phenomenon of self-induced transparency (SIT). Separately, in the regime where both light and atoms are fully treated quantum mechanically, quantum few-photon bound states are known to be a ubiquitous phenomenon that arises in different systems such as atoms coupled to chiral or bidirectional waveguides, and in Rydberg atomic media. In the specific case of two-level atoms coupled to a chiral waveguide, a recent analysis based on Bethe ansatz has established that SIT emerges from the quantum realm as a superposition of quantum many-photon bound states. Beyond this case, however, the nature of any connection between the full quantum many-body regime and semi-classical behavior has not been established. Here, we employ a general spin-model formulation of quantum atom-light interfaces to numerically investigate this problem, taking advantage of the fact that this approach readily allows for powerful many-body simulations based on matrix product states (MPS). We first analytically derive the two-photon bound state dispersion relation for a variety of atom-light interfaces, and then proceed to numerically investigate the multi-excitation bound states dynamics. Interestingly, for all the specific systems studied, we find that the large-photon number limit always coincides with the soliton phenomenon of self-induced transparency or immediate generalizations thereof.
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Submitted 9 April, 2022; v1 submitted 30 September, 2021;
originally announced October 2021.
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Renormalization group analysis of near-field induced dephasing of optical spin waves in an atomic medium
Authors:
Stefano Grava,
Yizun He,
Saijun Wu,
Darrick E. Chang
Abstract:
While typical theories of atom-light interactions treat the atomic medium as being smooth, it is well-known that microscopic optical effects driven by atomic granularity, dipole-dipole interactions, and multiple scattering can lead to important effects. Recently, for example, it was experimentally observed that these ingredients can lead to a fundamental, density-dependent dephasing of optical spi…
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While typical theories of atom-light interactions treat the atomic medium as being smooth, it is well-known that microscopic optical effects driven by atomic granularity, dipole-dipole interactions, and multiple scattering can lead to important effects. Recently, for example, it was experimentally observed that these ingredients can lead to a fundamental, density-dependent dephasing of optical spin waves in a disordered atomic medium. Here, we go beyond the short-time and dilute limits considered previously, to develop a comprehensive theory of dephasing dynamics for arbitrary times and atomic densities. In particular, we develop a novel, non-perturbative theory based on strong disorder renormalization group, in order to quantitatively predict the dominant role that near-field optical interactions between nearby neighbors has in driving the dephasing process. This theory also enables one to capture the key features of the many-atom dephasing dynamics in terms of an effective single-atom model. These results should shed light on the limits imposed by near-field interactions on quantum optical phenomena in dense atomic media, and illustrate the promise of strong disorder renormalization group as a method of dealing with complex microscopic optical phenomena in such systems.
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Submitted 20 August, 2021;
originally announced August 2021.
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Optomechanical strong coupling between a single cavity photon and a single atom
Authors:
Javier Argüello-Luengo,
Darrick E. Chang
Abstract:
Single atoms coupled to a cavity offer unique opportunities as quantum optomechanical devices because of their small mass and strong interaction with light. A particular regime of interest in optomechanics is that of "single-photon strong coupling," where motional displacements on the order of the zero-point uncertainty are sufficient to shift the cavity resonance frequency by more than its linewi…
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Single atoms coupled to a cavity offer unique opportunities as quantum optomechanical devices because of their small mass and strong interaction with light. A particular regime of interest in optomechanics is that of "single-photon strong coupling," where motional displacements on the order of the zero-point uncertainty are sufficient to shift the cavity resonance frequency by more than its linewidth. In many cavity QED platforms, however, this is unfeasible due to the large cavity linewidth. Here, we propose an alternative route in such systems, which instead relies on the coupling of atomic motion to the much narrower cavity-dressed atomic resonance frequency. We discuss and optimize the conditions in which the scattering properties of single photons from the atom-cavity system become highly entangled with the atomic motional wave function. We also analyze the prominent observable features of this optomechanical strong coupling, which include a per-photon motional heating that is significantly larger than the single-photon recoil energy, as well as mechanically-induced oscillations in time of the second-order correlation function of the emitted light. This physics should be realizable in current experimental setups, such as trapped atoms coupled to photonic crystal cavities, and more broadly opens the door to realizing qualitatively different phenomena beyond what has been observed in optomechanical systems thus far.
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Submitted 7 August, 2021;
originally announced August 2021.
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Superradiant detection of microscopic optical dipolar interactions
Authors:
Lingjing Ji,
Yizun He,
Qingnan Cai,
Zhening Fang,
Yuzhuo Wang,
Liyang Qiu,
Lei Zhou,
Saijun Wu,
Stefano Grava,
Darrick E. Chang
Abstract:
The interaction between light and cold atoms is a complex phenomenon potentially featuring many-body resonant dipole interactions. A major obstacle toward exploring these quantum resources of the system is macroscopic light propagation effects, which not only limit the available time for the microscopic correlations to locally build up, but also create a directional, superradiant emission backgrou…
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The interaction between light and cold atoms is a complex phenomenon potentially featuring many-body resonant dipole interactions. A major obstacle toward exploring these quantum resources of the system is macroscopic light propagation effects, which not only limit the available time for the microscopic correlations to locally build up, but also create a directional, superradiant emission background whose variations can overwhelm the microscopic effects. In this Letter, we demonstrate a method to perform ``background-free'' detection of the microscopic optical dynamics in a laser-cooled atomic ensemble. This is made possible by transiently suppressing the macroscopic optical propagation over a substantial time, before a recall of superradiance that imprints the effect of the accumulated microscopic dynamics into an efficiently detectable outgoing field. We apply this technique to unveil and precisely characterize a density-dependent, microscopic dipolar dephasing effect that generally limits the lifetime of optical spin-wave order in ensemble-based atom-light interfaces.
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Submitted 12 October, 2023; v1 submitted 26 January, 2021;
originally announced January 2021.
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Atomic spin-wave control and spin-dependent kicks with shaped subnanosecond pulses
Authors:
Yizun He,
Lingjing Ji,
Yuzhuo Wang,
Liyang Qiu,
Jian Zhao,
Yudi Ma,
Xing Huang,
Saijun Wu,
Darrick E. Chang
Abstract:
The absorption of traveling photons resonant with electric dipole transitions of an atomic gas naturally leads to electric dipole spin wave excitations. For a number of applications, it would be highly desirable to shape and coherently control the spatial waveform of the spin waves before spontaneous emission can occur. This paper details a recently developed optical control technique to achieve t…
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The absorption of traveling photons resonant with electric dipole transitions of an atomic gas naturally leads to electric dipole spin wave excitations. For a number of applications, it would be highly desirable to shape and coherently control the spatial waveform of the spin waves before spontaneous emission can occur. This paper details a recently developed optical control technique to achieve this goal, where counter-propagating, shaped sub-nanosecond pulses impart sub-wavelength geometric phases to the spin waves by cyclically driving an auxiliary transition. In particular, we apply this technique to reversibly shift the wave vector of a spin wave on the $D2$ line of laser-cooled $^{87}$Rb atoms, by driving an auxiliary $D1$ transition with shape-optimized pulses, so as to shut off and recall superradiance on demand. We investigate a spin-dependent momentum transfer during the spin-wave control process, which leads to a transient optical force as large as $\sim 1\hbar k$/ns, and study the limitations to the achieved $70\sim 75\%$ spin wave control efficiency by jointly characterizing the spin-wave control and matterwave acceleration. Aided by numerical modeling, we project potential future improvements of the control fidelity to the $99\%$ level when the atomic states are better prepared and by equipping a faster and more powerful pulse shaper. Our technique also enables a background-free measurement of the superradiant emission to unveil the precise scaling of the emission intensity and decay rate with optical depth.
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Submitted 26 December, 2020; v1 submitted 29 October, 2020;
originally announced October 2020.
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Dynamics of many-body photon bound states in chiral waveguide QED
Authors:
Sahand Mahmoodian,
Giuseppe Calajó,
Darrick E. Chang,
Klemens Hammerer,
Anders S. Sørensen
Abstract:
We theoretically study the few- and many-body dynamics of photons in chiral waveguides. In particular, we examine pulse propagation through a system of $N$ two-level systems chirally coupled to a waveguide. We show that the system supports correlated multi-photon bound states, which have a well-defined photon number $n$ and propagate through the system with a group delay scaling as $1/n^2$. This h…
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We theoretically study the few- and many-body dynamics of photons in chiral waveguides. In particular, we examine pulse propagation through a system of $N$ two-level systems chirally coupled to a waveguide. We show that the system supports correlated multi-photon bound states, which have a well-defined photon number $n$ and propagate through the system with a group delay scaling as $1/n^2$. This has the interesting consequence that, during propagation, an incident coherent state pulse breaks up into different bound state components that can become spatially separated at the output in a sufficiently long system. For sufficiently many photons and sufficiently short systems, we show that linear combinations of $n$-body bound states recover the well-known phenomenon of mean-field solitons in self-induced transparency. For longer systems, however, the solitons break apart through quantum correlated dynamics. Our work thus covers the entire spectrum from few-photon quantum propagation, to genuine quantum many-body (atom and photon) phenomena, and ultimately the quantum-to-classical transition. Finally, we demonstrate that the bound states can undergo elastic scattering with additional photons. Together, our results demonstrate that photon bound states are truly distinct physical objects emerging from the most elementary light-matter interaction between photons and two-level emitters. Our work opens the door to studying quantum many-body physics and soliton physics with photons in chiral waveguide QED.
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Submitted 7 May, 2020; v1 submitted 13 October, 2019;
originally announced October 2019.
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Geometric control of collective spontaneous emission
Authors:
Yizun He,
Lingjing Ji,
Yuzhuo Wang,
Liyang Qiu,
Jian Zhao,
Yudi Ma,
Xing Huang,
Darrick E. Chang,
Saijun Wu
Abstract:
Dipole spin-wave states of atomic ensembles with wave vector ${\bf k}(ω)$ mismatched from the dispersion relation of light are difficult to access by far-field excitation but may support rich phenomena beyond the traditional phase-matched scenario in quantum optics. We propose and demonstrate an optical technique to efficiently access these states. In particular, subnanosecond laser pulses shaped…
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Dipole spin-wave states of atomic ensembles with wave vector ${\bf k}(ω)$ mismatched from the dispersion relation of light are difficult to access by far-field excitation but may support rich phenomena beyond the traditional phase-matched scenario in quantum optics. We propose and demonstrate an optical technique to efficiently access these states. In particular, subnanosecond laser pulses shaped by a home-developed wideband modulation method are applied to shift the spin wave in ${\bf k}$ space with state-dependent geometric phase patterning, in an error-resilient fashion and on timescales much faster than spontaneous emission. We verify this control through the redirection, switch off, and recall of collectively enhanced emission from a $^{87}$Rb gas with $\sim 75\%$ single-step efficiency. Our work represents a first step toward efficient control of electric dipole spin waves for studying many-body dissipative dynamics of excited gases, as well as for numerous quantum optical applications.
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Submitted 18 November, 2020; v1 submitted 5 October, 2019;
originally announced October 2019.
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Optical waveguiding by atomic entanglement in multilevel atom arrays
Authors:
A. Asenjo-Garcia,
H. J. Kimble,
D. E. Chang
Abstract:
The optical properties of sub-wavelength arrays of atoms or other quantum emitters have attracted significant interest recently. For example, the strong constructive or destructive interference of emitted light enables arrays to function as nearly perfect mirrors, support topological edge states, and allow for exponentially better quantum memories. In these proposals, the assumed atomic structure…
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The optical properties of sub-wavelength arrays of atoms or other quantum emitters have attracted significant interest recently. For example, the strong constructive or destructive interference of emitted light enables arrays to function as nearly perfect mirrors, support topological edge states, and allow for exponentially better quantum memories. In these proposals, the assumed atomic structure was simple, consisting of a unique electronic ground state. Within linear optics, the system is then equivalent to a periodic array of classical dielectric particles, whose periodicity supports the emergence of guided modes. However, it has not been known whether such phenomena persist in the presence of hyperfine structure, as exhibited by most quantum emitters. Here, we show that waveguiding can arise from rich atomic entanglement as a quantum many-body effect, and elucidate the necessary conditions. Our work represents a significant step forward in understanding collective effects in arrays of atoms with realistic electronic structure.
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Submitted 19 December, 2019; v1 submitted 5 June, 2019;
originally announced June 2019.
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Topological quantum optics using atom-like emitter arrays coupled to photonic crystals
Authors:
Janos Perczel,
Johannes Borregaard,
Darrick E. Chang,
Susanne F. Yelin,
Mikhail D. Lukin
Abstract:
We propose a nanophotonic platform for topological quantum optics. Our system is composed of a two-dimensional lattice of non-linear quantum emitters with optical transitions embedded in a photonic crystal slab. The emitters interact through the guided modes of the photonic crystal, and a uniform magnetic field gives rise to large topological band gaps and an almost completely flat topological ban…
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We propose a nanophotonic platform for topological quantum optics. Our system is composed of a two-dimensional lattice of non-linear quantum emitters with optical transitions embedded in a photonic crystal slab. The emitters interact through the guided modes of the photonic crystal, and a uniform magnetic field gives rise to large topological band gaps and an almost completely flat topological band. Topological edge states arise on the boundaries of the system that are protected by the large gap against missing lattice sites and to the inhomogeneous broadening of emitters. These results pave the way for exploring topological many-body states in quantum optical systems.
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Submitted 10 April, 2019; v1 submitted 29 October, 2018;
originally announced October 2018.
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Single-photon bound states in atomic ensembles
Authors:
Yidan Wang,
Michael J. Gullans,
Antoine Browaeys,
J. V. Porto,
Darrick E. Chang,
Alexey V. Gorshkov
Abstract:
We illustrate the existence of single-excitation bound states for propagating photons interacting with $N$ two-level atoms. These bound states can be calculated from an effective spin model, and their existence relies on dissipation in the system. The appearance of these bound states is in a one-to-one correspondence with zeros in the single-photon transmission and with divergent bunching in the s…
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We illustrate the existence of single-excitation bound states for propagating photons interacting with $N$ two-level atoms. These bound states can be calculated from an effective spin model, and their existence relies on dissipation in the system. The appearance of these bound states is in a one-to-one correspondence with zeros in the single-photon transmission and with divergent bunching in the second-order photon-photon correlation function. We also formulate a dissipative version of Levinson's theorem for this system by looking at the relation between the number of bound states and the winding number of the transmission phases. This theorem allows a direct experimental measurement of the number of bound states using the measured transmission phases.
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Submitted 4 September, 2018;
originally announced September 2018.
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On the Decomposition of Forces
Authors:
Dong Eui Chang
Abstract:
We show that any continuously differentiable force is decomposed into the sum of a Rayleigh force and a gyroscopic force. We also extend this result to piecewise continuously differentiable forces. Our result improves the result on the decomposition of forces in a book by David Merkin and further extends it to piecewise continuously differentiable forces.
We show that any continuously differentiable force is decomposed into the sum of a Rayleigh force and a gyroscopic force. We also extend this result to piecewise continuously differentiable forces. Our result improves the result on the decomposition of forces in a book by David Merkin and further extends it to piecewise continuously differentiable forces.
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Submitted 10 July, 2018;
originally announced July 2018.
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Photonic Band Structure of Two-dimensional Atomic Lattices
Authors:
Janos Perczel,
Johannes Borregaard,
Darrick E. Chang,
Hannes Pichler,
Susanne F. Yelin,
Peter Zoller,
Mikhail D. Lukin
Abstract:
Two-dimensional atomic arrays exhibit a number of intriguing quantum optical phenomena, including subradiance, nearly perfect reflection of radiation and long-lived topological edge states. Studies of emission and scattering of photons in such lattices require complete treatment of the radiation pattern from individual atoms, including long-range interactions. We describe a systematic approach to…
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Two-dimensional atomic arrays exhibit a number of intriguing quantum optical phenomena, including subradiance, nearly perfect reflection of radiation and long-lived topological edge states. Studies of emission and scattering of photons in such lattices require complete treatment of the radiation pattern from individual atoms, including long-range interactions. We describe a systematic approach to perform the calculations of collective energy shifts and decay rates in the presence of such long-range interactions for arbitrary two-dimensional atomic lattices. As applications of our method, we investigate the topological properties of atomic lattices both in free-space and near plasmonic surfaces.
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Submitted 10 August, 2017;
originally announced August 2017.
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Topological Quantum Optics in Two-Dimensional Atomic Arrays
Authors:
Janos Perczel,
Johannes Borregaard,
Darrick E. Chang,
Hannes Pichler,
Susanne F. Yelin,
Peter Zoller,
Mikhail D. Lukin
Abstract:
We demonstrate that two-dimensional atomic emitter arrays with subwavelength spacing constitute topologically protected quantum optical systems where the photon propagation is robust against large imperfections while losses associated with free space emission are strongly suppressed. Breaking time-reversal symmetry with a magnetic field results in gapped photonic bands with non-trivial Chern numbe…
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We demonstrate that two-dimensional atomic emitter arrays with subwavelength spacing constitute topologically protected quantum optical systems where the photon propagation is robust against large imperfections while losses associated with free space emission are strongly suppressed. Breaking time-reversal symmetry with a magnetic field results in gapped photonic bands with non-trivial Chern numbers and topologically protected, long-lived edge states. Due to the inherent nonlinearity of constituent emitters, such systems provide a platform for exploring quantum optical analogues of interacting topological systems.
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Submitted 17 July, 2017; v1 submitted 14 March, 2017;
originally announced March 2017.
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Exponential improvement in photon storage fidelities using subradiance and "selective radiance" in atomic arrays
Authors:
A. Asenjo-Garcia,
M. Moreno-Cardoner,
A. Albrecht,
H. J. Kimble,
D. E. Chang
Abstract:
A central goal within quantum optics is to realize efficient interactions between photons and atoms. A fundamental limit in nearly all applications based on such systems arises from spontaneous emission, in which photons are absorbed by atoms and then re-scattered into undesired channels. In typical treatments of atomic ensembles, it is assumed that this re-scattering occurs independently, and at…
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A central goal within quantum optics is to realize efficient interactions between photons and atoms. A fundamental limit in nearly all applications based on such systems arises from spontaneous emission, in which photons are absorbed by atoms and then re-scattered into undesired channels. In typical treatments of atomic ensembles, it is assumed that this re-scattering occurs independently, and at a rate given by a single isolated atom, which in turn gives rise to standard limits of fidelity in applications such as quantum memories or quantum gates. However, this assumption can be violated. In particular, spontaneous emission of a collective atomic excitation can be significantly suppressed through strong interference in emission. Thus far the physics underlying the phenomenon of subradiance and techniques to exploit it have not been well-understood. In this work, we provide a comprehensive treatment of this problem. First, we show that in ordered atomic arrays in free space, subradiant states acquire an interpretation in terms of optical modes that are guided by the array, which only emit due to scattering from the ends of the finite chain. We also elucidate the properties of subradiant states in the many-excitation limit. Finally, we introduce the new concept of selective radiance. Whereas subradiant states experience a reduced coupling to all optical modes, selectively radiant states are tailored to simultaneously radiate efficiently into a desired channel while scattering into undesired channels is suppressed, thus enabling an enhanced atom-light interface. We show that these states naturally appear in chains of atoms coupled to nanophotonic structures, and we analyze the performance of photon storage exploiting such states. We find that selectively radiant states allow for a photon storage error that scales exponentially better with number of atoms than previously known bounds.
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Submitted 29 August, 2017; v1 submitted 9 March, 2017;
originally announced March 2017.
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Atom-light interactions in quasi-1D nanostructures: a Green's function perspective
Authors:
A. Asenjo-Garcia,
J. D. Hood,
D. E. Chang,
H. J. Kimble
Abstract:
Based on a formalism that describes atom-light interactions in terms of the classical electromagnetic Green's function, we study the optical response of atoms and other quantum emitters coupled to one-dimensional photonic structures, such as cavities, waveguides, and photonic crystals. We demonstrate a clear mapping between the transmission spectra and the local Green's function that allows to ide…
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Based on a formalism that describes atom-light interactions in terms of the classical electromagnetic Green's function, we study the optical response of atoms and other quantum emitters coupled to one-dimensional photonic structures, such as cavities, waveguides, and photonic crystals. We demonstrate a clear mapping between the transmission spectra and the local Green's function that allows to identify signatures of dispersive and dissipative interactions between atoms. We also demonstrate the applicability of our analysis to problems involving three-level atoms, such as electromagnetically induced transparency. Finally we examine recent experiments, and anticipate future observations of atom-atom interactions in photonic bandgaps.
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Submitted 7 March, 2017; v1 submitted 15 June, 2016;
originally announced June 2016.
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The Roles of Substrate vs Nonlocal Optical Nonlinearities in the Excitation of Surface Plasmons in Graphene
Authors:
Thomas J. Constant,
Craig J. Tollerton,
Euan Hendry,
Darrick E. Chang
Abstract:
It has recently been demonstrated that difference frequency mixing (DFM) can generate surface plasmons in graphene [1]. Here, we present detailed calculations comparing the contributions to this effect from substrate and from graphene nonlinearities. Our calculations show that the substrate (quartz) nonlinearity gives rise to a surface plasmon intensity that is around twelve orders of magnitude sm…
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It has recently been demonstrated that difference frequency mixing (DFM) can generate surface plasmons in graphene [1]. Here, we present detailed calculations comparing the contributions to this effect from substrate and from graphene nonlinearities. Our calculations show that the substrate (quartz) nonlinearity gives rise to a surface plasmon intensity that is around twelve orders of magnitude smaller than that arising from the intrinsic graphene response. This surprisingly efficient intrinsic process, given the centrosymmetric structure of graphene, arises almost entirely due to non-local contributions to the second order optical nonlinearity of graphene.
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Submitted 5 May, 2016;
originally announced May 2016.
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Atom-atom interactions around the band edge of a photonic crystal waveguide
Authors:
J. D. Hood,
A. Goban,
A. Asenjo-Garcia,
M. Lu,
S. -P. Yu,
D. E. Chang,
H. J. Kimble
Abstract:
Tailoring the interactions between quantum emitters and single photons constitutes one of the cornerstones of quantum optics. Coupling a quantum emitter to the band edge of a photonic crystal waveguide (PCW) provides a unique platform for tuning these interactions. In particular, the crossover from propagating fields $E(x) \propto e^{\pm ik_x x}$ outside the bandgap to localized fields…
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Tailoring the interactions between quantum emitters and single photons constitutes one of the cornerstones of quantum optics. Coupling a quantum emitter to the band edge of a photonic crystal waveguide (PCW) provides a unique platform for tuning these interactions. In particular, the crossover from propagating fields $E(x) \propto e^{\pm ik_x x}$ outside the bandgap to localized fields $E(x) \propto e^{-κ_x |x|}$ within the bandgap should be accompanied by a transition from largely dissipative atom-atom interactions to a regime where dispersive atom-atom interactions are dominant. Here, we experimentally observe this transition for the first time by shifting the band edge frequency of the PCW relative to the $\rm D_1$ line of atomic cesium for $\bar{N}=3.0\pm 0.5$ atoms trapped along the PCW. Our results are the initial demonstration of this new paradigm for coherent atom-atom interactions with low dissipation into the guided mode.
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Submitted 30 August, 2017; v1 submitted 8 March, 2016;
originally announced March 2016.
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Theory of self-induced back-action optical trapping in nanophotonic systems
Authors:
Lukas Neumeier,
Romain Quidant,
Darrick E. Chang
Abstract:
Optical trapping is an indispensable tool in physics and the life sciences. However, there is a clear trade off between the size of a particle to be trapped, its spatial confinement, and the intensities required. This is due to the decrease in optical response of smaller particles and the diffraction limit that governs the spatial variation of optical fields. It is thus highly desirable to find te…
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Optical trapping is an indispensable tool in physics and the life sciences. However, there is a clear trade off between the size of a particle to be trapped, its spatial confinement, and the intensities required. This is due to the decrease in optical response of smaller particles and the diffraction limit that governs the spatial variation of optical fields. It is thus highly desirable to find techniques that surpass these bounds. Recently, a number of experiments using nanophotonic cavities have observed a qualitatively different trapping mechanism described as "self-induced back-action trapping" (SIBA). In these systems, the particle motion couples to the resonance frequency of the cavity, which results in a strong interplay between the intra-cavity field intensity and the forces exerted. Here, we provide a theoretical description that for the first time captures the remarkable range of consequences. In particular, we show that SIBA can be exploited to yield dynamic reshaping of trap potentials, strongly sub-wavelength trap features, and significant reduction of intensities seen by the particle, which should have important implications for future trapping technologies
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Submitted 11 May, 2015;
originally announced May 2015.
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All-Optical Generation of Surface Plasmons in Graphene
Authors:
Thomas J. Constant,
Samuel M. Hornett,
Darrick E. Chang,
Euan Hendry
Abstract:
Here we present an all-optical plasmon coupling scheme, utilising the intrinsic nonlinear optical response of graphene. We demonstrate coupling of free-space, visible light pulses to the surface plasmons in a planar, un-patterned graphene sheet by using nonlinear wave mixing to match both the wavevector and energy of the surface wave. By carefully controlling the phase-matching conditions, we show…
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Here we present an all-optical plasmon coupling scheme, utilising the intrinsic nonlinear optical response of graphene. We demonstrate coupling of free-space, visible light pulses to the surface plasmons in a planar, un-patterned graphene sheet by using nonlinear wave mixing to match both the wavevector and energy of the surface wave. By carefully controlling the phase-matching conditions, we show that one can excite surface plasmons with a defined wavevector and direction across a large frequency range, with an estimated photon efficiency in our experiments approaching $10^{-5}$.
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Submitted 7 July, 2015; v1 submitted 1 May, 2015;
originally announced May 2015.
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Second-order quantum nonlinear optical processes in single graphene nanostructures and arrays
Authors:
Marco T. Manzoni,
Iván Silveiro,
F. Javier García de Abajo,
Darrick E. Chang
Abstract:
Intense efforts have been made in recent years to realize nonlinear optical interactions at the single-photon level. Much of this work has focused on achieving strong third-order nonlinearities, such as by using single atoms or other quantum emitters while the possibility of achieving strong second-order nonlinearities remains unexplored. Here, we describe a novel technique to realize such nonline…
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Intense efforts have been made in recent years to realize nonlinear optical interactions at the single-photon level. Much of this work has focused on achieving strong third-order nonlinearities, such as by using single atoms or other quantum emitters while the possibility of achieving strong second-order nonlinearities remains unexplored. Here, we describe a novel technique to realize such nonlinearities using graphene, exploiting the strong per-photon fields associated with tightly confined graphene plasmons in combination with spatially nonlocal nonlinear optical interactions. We show that in properly designed graphene nanostructures, these conditions enable extremely strong internal down-conversion between a single quantized plasmon and an entangled plasmon pair, or the reverse process of second harmonic generation. A separate issue is how such strong internal nonlinearities can be observed, given the nominally weak coupling between these plasmon resonances and free-space radiative fields. On one hand, by using the collective coupling to radiation of nanostructure arrays, we show that the internal nonlinearities can manifest themselves as efficient frequency conversion of radiative fields at extremely low input powers. On the other hand, the development of techniques to efficiently couple to single nanostructures would allow these nonlinear processes to occur at the level of single input photons.
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Submitted 24 August, 2015; v1 submitted 17 June, 2014;
originally announced June 2014.
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Atom-Light Interactions in Photonic Crystals
Authors:
A. Goban,
C. -L. Hung,
S. -P. Yu,
J. D. Hood,
J. A. Muniz,
J. H. Lee,
M. J. Martin,
A. C. McClung,
K. S. Choi,
D. E. Chang,
O. Painter,
H. J. Kimble
Abstract:
The integration of nanophotonics and atomic physics has been a long-sought goal that would open new frontiers for optical physics. Here, we report the development of the first integrated optical circuit with a photonic crystal capable of both localizing and interfacing atoms with guided photons in the device. By aligning the optical bands of a photonic crystal waveguide (PCW) with selected atomic…
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The integration of nanophotonics and atomic physics has been a long-sought goal that would open new frontiers for optical physics. Here, we report the development of the first integrated optical circuit with a photonic crystal capable of both localizing and interfacing atoms with guided photons in the device. By aligning the optical bands of a photonic crystal waveguide (PCW) with selected atomic transitions, our platform provides new opportunities for novel quantum transport and many-body phenomena by way of photon-mediated atomic interactions along the PCW. From reflection spectra measured with average atom number N = 1.1$\pm$0.4, we infer that atoms are localized within the PCW by Casimir-Polder and optical dipole forces. The fraction of single-atom radiative decay into the PCW is $Γ_{\rm 1D}/Γ'$ = 0.32$\pm$0.08, where $Γ_{1D}$ is the rate of emission into the guided mode and $Γ'$ is the decay rate into all other channels. $Γ_{\rm 1D}/Γ'$ is quoted without enhancement due to an external cavity and is unprecedented in all current atom-photon interfaces.
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Submitted 12 December, 2013;
originally announced December 2013.
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Trapping atoms using nanoscale quantum vacuum forces
Authors:
D. E. Chang,
K. Sinha,
J. M. Taylor,
H. J. Kimble
Abstract:
Quantum vacuum forces dictate the interaction between individual atoms and dielectric surfaces at nanoscale distances. For example, their large strengths typically overwhelm externally applied forces, which makes it challenging to controllably interface cold atoms with nearby nanophotonic systems. Here, we show that it is possible to tailor the vacuum forces themselves to provide strong trapping p…
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Quantum vacuum forces dictate the interaction between individual atoms and dielectric surfaces at nanoscale distances. For example, their large strengths typically overwhelm externally applied forces, which makes it challenging to controllably interface cold atoms with nearby nanophotonic systems. Here, we show that it is possible to tailor the vacuum forces themselves to provide strong trapping potentials. The trapping scheme takes advantage of the attractive ground state potential and adiabatic dressing with an excited state whose potential is engineered to be resonantly enhanced and repulsive. This procedure yields a strong metastable trap, with the fraction of excited state population scaling inversely with the quality factor of the resonance of the dielectric structure. We analyze realistic limitations to the trap lifetime and discuss possible applications that might emerge from the large trap depths and nanoscale confinement.
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Submitted 22 October, 2013;
originally announced October 2013.
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Lyapunov-based Low-thrust Optimal Orbit Transfer: An approach in Cartesian coordinates
Authors:
Hantian Zhang,
Dong Eui Chang,
Qingjie Cao
Abstract:
This paper presents a simple approach to low-thrust optimal-fuel and optimal-time transfer problems between two elliptic orbits using the Cartesian coordinates system. In this case, an orbit is described by its specific angular momentum and Laplace vectors with a free injection point. Trajectory optimization with the pseudospectral method and nonlinear programming are supported by the initial gues…
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This paper presents a simple approach to low-thrust optimal-fuel and optimal-time transfer problems between two elliptic orbits using the Cartesian coordinates system. In this case, an orbit is described by its specific angular momentum and Laplace vectors with a free injection point. Trajectory optimization with the pseudospectral method and nonlinear programming are supported by the initial guess generated from the Chang-Chichka-Marsden Lyapunov-based transfer controller. This approach successfully solves several low-thrust optimal problems. Numerical results show that the Lyapunov-based initial guess overcomes the difficulty in optimization caused by the strong oscillation of variables in the Cartesian coordinates system. Furthermore, a comparison of the results shows that obtaining the optimal transfer solution through the polynomial approximation by utilizing Cartesian coordinates is easier than using orbital elements, which normally produce strongly nonlinear equations of motion. In this paper, the Earth's oblateness and shadow effect are not taken into account.
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Submitted 15 October, 2013;
originally announced October 2013.
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Single-photon nonlinear optics with graphene plasmons
Authors:
M. Gullans,
D. E. Chang,
F. H. L. Koppens,
F. J. García de Abajo,
M. D. Lukin
Abstract:
We show that it is possible to realize significant nonlinear optical interactions at the few photon level in graphene nanostructures. Our approach takes advantage of the electric field enhancement associated with the strong confinement of graphene plasmons and the large intrinsic nonlinearity of graphene. Such a system could provide a powerful platform for quantum nonlinear optical control of ligh…
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We show that it is possible to realize significant nonlinear optical interactions at the few photon level in graphene nanostructures. Our approach takes advantage of the electric field enhancement associated with the strong confinement of graphene plasmons and the large intrinsic nonlinearity of graphene. Such a system could provide a powerful platform for quantum nonlinear optical control of light. As an example, we consider an integrated optical device that exploits this large nonlinearity to realize a single photon switch.
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Submitted 8 August, 2014; v1 submitted 10 September, 2013;
originally announced September 2013.
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On the Self-Recovery Phenomenon in the Process of Diffusion
Authors:
Dong Eui Chang,
Soo Jeon
Abstract:
We report a new phenomenon, called self-recovery, in the process of diffusion in a region with boundary. Suppose that a diffusing quantity is uniformly distributed initially and then gets excited by the change in the boundary values over a time interval. When the boundary values return to their initial values and stop varying afterwards, the value of a physical quantity related to the diffusion au…
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We report a new phenomenon, called self-recovery, in the process of diffusion in a region with boundary. Suppose that a diffusing quantity is uniformly distributed initially and then gets excited by the change in the boundary values over a time interval. When the boundary values return to their initial values and stop varying afterwards, the value of a physical quantity related to the diffusion automatically comes back to its original value. This self-recovery phenomenon has been discovered and fairly well understood for finite-dimensional mechanical systems with viscous damping. In this paper, we show that it also occurs in the process of diffusion. Several examples are provided from fluid flows, quasi-static electromagnetic fields and heat conduction. In particular, our result in fluid flows provides a dynamic explanation for the famous experiment by Sir G.I. Taylor with glycerine in an annulus on kinematic reversibility of low-Reynolds-number flows.
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Submitted 5 June, 2013; v1 submitted 28 May, 2013;
originally announced May 2013.
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On the Damping-Induced Self-Recovery Phenomenon in Mechanical Systems with Several Unactuated Cyclic Variables
Authors:
Dong Eui Chang,
Soo Jeon
Abstract:
The damping-induced self-recovery phenomenon refers to the fundamental property of underactuated mechanical systems: if an unactuated cyclic variable is under a viscous damping-like force and the system starts from rest, then the cyclic variable will always move back to its initial condition as the actuated variables come to stop. The regular momentum conservation phenomenon can be viewed as the l…
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The damping-induced self-recovery phenomenon refers to the fundamental property of underactuated mechanical systems: if an unactuated cyclic variable is under a viscous damping-like force and the system starts from rest, then the cyclic variable will always move back to its initial condition as the actuated variables come to stop. The regular momentum conservation phenomenon can be viewed as the limit of the damping-induced self-recovery phenomenon in the sense that the self-recovery phenomenon disappears as the damping goes to zero. This paper generalizes the past result on damping-induced self-recovery for the case of a single unactuated cyclic variable to the case of multiple unactuated cyclic variables. We characterize a class of external forces that induce new conserved quantities, which we call the damping-induced momenta. The damping-induced momenta yield first-order asymptotically stable dynamics for the unactuated cyclic variables under some conditions, thereby inducing the self-recovery phenomenon. It is also shown that the viscous damping-like forces impose bounds on the range of trajectories of the unactuated cyclic variables. Two examples are presented to demonstrate the analytical discoveries: the planar pendulum with gimbal actuators and the three-link planar manipulator on a horizontal plane.
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Submitted 8 February, 2013;
originally announced February 2013.
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Trapped Atoms in One-Dimensional Photonic Crystals
Authors:
C. -L. Hung,
S. M. Meenehan,
D. E. Chang,
O. Painter,
H. J. Kimble
Abstract:
We describe one-dimensional photonic crystals that support a guided mode suitable for atom trapping within a unit cell, as well as a second probe mode with strong atom-photon interactions. A new hybrid trap is analyzed that combines optical and Casimir-Polder forces to form stable traps for neutral atoms in dielectric nanostructures. By suitable design of the band structure, the atomic spontaneous…
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We describe one-dimensional photonic crystals that support a guided mode suitable for atom trapping within a unit cell, as well as a second probe mode with strong atom-photon interactions. A new hybrid trap is analyzed that combines optical and Casimir-Polder forces to form stable traps for neutral atoms in dielectric nanostructures. By suitable design of the band structure, the atomic spontaneous emission rate into the probe mode can exceed the rate into all other modes by more than tenfold. The unprecedented single-atom reflectivity $r_0 \gtrsim 0.9$ for the guided probe field should enable diverse investigations of photon-mediated interactions for 1D atom chains and cavity QED.
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Submitted 22 January, 2013;
originally announced January 2013.
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Self-organization of atoms along a nanophotonic waveguide
Authors:
D. E. Chang,
J. I. Cirac,
H. J. Kimble
Abstract:
Atoms coupled to nanophotonic interfaces represent an exciting frontier for the investigation of quantum light-matter interactions. While most work has considered the interaction between statically positioned atoms and light, here we demonstrate that a wealth of phenomena can arise from the self-consistent interaction between atomic internal states, optical scattering, and atomic forces. We consid…
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Atoms coupled to nanophotonic interfaces represent an exciting frontier for the investigation of quantum light-matter interactions. While most work has considered the interaction between statically positioned atoms and light, here we demonstrate that a wealth of phenomena can arise from the self-consistent interaction between atomic internal states, optical scattering, and atomic forces. We consider in detail the case of atoms coupled to a one-dimensional nanophotonic waveguide, and show that this interplay gives rise to self-organization of atomic positions along the waveguide, which can be probed experimentally through distinct characteristics of the reflection and transmission spectra.
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Submitted 24 November, 2012;
originally announced November 2012.
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Nanoplasmonic Lattices for Ultracold atoms
Authors:
M. Gullans,
T. Tiecke,
D. E. Chang,
J. Feist,
J. D. Thompson,
J. I. Cirac,
P. Zoller,
M. D. Lukin
Abstract:
We propose to use sub-wavelength confinement of light associated with the near field of plasmonic systems to create nanoscale optical lattices for ultracold atoms. Our approach combines the unique coherence properties of isolated atoms with the sub-wavelength manipulation and strong light-matter interaction associated with nano-plasmonic systems. It allows one to considerably increase the energy s…
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We propose to use sub-wavelength confinement of light associated with the near field of plasmonic systems to create nanoscale optical lattices for ultracold atoms. Our approach combines the unique coherence properties of isolated atoms with the sub-wavelength manipulation and strong light-matter interaction associated with nano-plasmonic systems. It allows one to considerably increase the energy scales in the realization of Hubbard models and to engineer effective long-range interactions in coherent and dissipative many-body dynamics. Realistic imperfections and potential applications are discussed.
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Submitted 25 July, 2014; v1 submitted 30 August, 2012;
originally announced August 2012.
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Enhancement of mechanical Q-factors by optical trapping
Authors:
K. -K. Ni,
R. Norte,
D. J. Wilson,
J. D. Hood,
D. E. Chang,
O. Painter,
H. J. Kimble
Abstract:
The quality factor of a mechanical resonator is an important figure of merit for various sensing applications and for observing quantum behavior. Here, we demonstrate a technique to push the quality factor of a micro-mechanical resonator beyond conventional material and fabrication limits by using an optical field to stiffen or "trap" a particular motional mode. Optical forces increase the oscilla…
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The quality factor of a mechanical resonator is an important figure of merit for various sensing applications and for observing quantum behavior. Here, we demonstrate a technique to push the quality factor of a micro-mechanical resonator beyond conventional material and fabrication limits by using an optical field to stiffen or "trap" a particular motional mode. Optical forces increase the oscillation frequency by storing most of the mechanical energy in a lossless optical potential, thereby strongly diluting the effect of material dissipation. By using a 130 nm thick SiO$_2$ disk as a suspended pendulum, we achieve an increase in the pendulum center-of-mass frequency from 6.2 kHz to 145 kHz. The corresponding quality factor increases 50-fold from its intrinsic value to a final value of $Q=5.8(1.1)\times 10^5$, representing more than an order of magnitude improvement over the conventional limits of SiO$_2$ for this geometry. Our technique may enable new opportunities for mechanical sensing and facilitate observations of quantum behavior in this class of mechanical systems.
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Submitted 9 January, 2012;
originally announced January 2012.
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Graphene plasmonics: A platform for strong light-matter interaction
Authors:
Frank H. L. Koppens,
Darrick E. Chang,
F. Javier Garcia de Abajo
Abstract:
Graphene plasmons provide a suitable alternative to noble-metal plasmons because they exhibit much larger confinement and relatively long propagation distances, with the advantage of being highly tunable via electrostatic gating. We report strong light- matter interaction assisted by graphene plasmons, and in particular, we predict unprecedented high decay rates of quantum emitters in the proximit…
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Graphene plasmons provide a suitable alternative to noble-metal plasmons because they exhibit much larger confinement and relatively long propagation distances, with the advantage of being highly tunable via electrostatic gating. We report strong light- matter interaction assisted by graphene plasmons, and in particular, we predict unprecedented high decay rates of quantum emitters in the proximity of a carbon sheet, large vacuum Rabi splitting and Purcell factors, and extinction cross sections exceeding the geometrical area in graphene ribbons and nanometer-sized disks. Our results provide the basis for the emerging and potentially far-reaching field of graphene plasmonics, offering an ideal platform for cavity quantum electrodynamics and supporting the possibility of single-molecule, single-plasmon devices.
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Submitted 11 April, 2011;
originally announced April 2011.
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Trapping and manipulation of isolated atoms using nanoscale plasmonic structures
Authors:
D. E. Chang,
J. D. Thompson,
H. Park,
V. Vuletic,
A. S. Zibrov,
P. Zoller,
M. D. Lukin
Abstract:
We propose and analyze a scheme to interface individual neutral atoms with nanoscale solid-state systems. The interface is enabled by optically trapping the atom via the strong near-field generated by a sharp metallic nanotip. We show that under realistic conditions, a neutral atom can be trapped with position uncertainties of just a few nanometers, and within tens of nanometers of other surface…
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We propose and analyze a scheme to interface individual neutral atoms with nanoscale solid-state systems. The interface is enabled by optically trapping the atom via the strong near-field generated by a sharp metallic nanotip. We show that under realistic conditions, a neutral atom can be trapped with position uncertainties of just a few nanometers, and within tens of nanometers of other surfaces. Simultaneously, the guided surface plasmon modes of the nanotip allow the atom to be optically manipulated, or for fluorescence photons to be collected, with very high efficiency. Finally, we analyze the surface forces and heating and decoherence rates acting on the trapped atom.
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Submitted 22 May, 2009;
originally announced May 2009.
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Broad-band spectral control of single photon sources using a nonlinear photonic crystal cavity
Authors:
Murray W. McCutcheon,
Darrick E. Chang,
Yinan Zhang,
Mikhail D. Lukin,
Marko Loncar
Abstract:
Motivated by developments in quantum information science, much recent effort has been directed toward coupling individual quantum emitters to optical microcavities. Such systems can be used to produce single photons on demand, enable nonlinear optical switching at a single photon level, and implement functional nodes of a quantum network, where the emitters serve as processing nodes and photons…
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Motivated by developments in quantum information science, much recent effort has been directed toward coupling individual quantum emitters to optical microcavities. Such systems can be used to produce single photons on demand, enable nonlinear optical switching at a single photon level, and implement functional nodes of a quantum network, where the emitters serve as processing nodes and photons are used for long-distance quantum communication. For many of these practical applications, it is important to develop techniques that allow one to generate outgoing single photons of desired frequency and bandwidth, enabling hybrid networks connecting different types of emitters and long-distance transmission over telecommunications wavelengths. Here, we propose a novel approach that makes use of a nonlinear optical resonator, in which the single photon originating from the atom-like emitter is directly converted into a photon with desired frequency and bandwidth using the intracavity nonlinearity. As specific examples, we discuss a high-finesse, TE-TM double-mode photonic crystal cavity design that allows for direct generation of single photons at telecom wavelengths starting from an InAs/GaAs quantum dot with a 950 nm transition wavelength, and a scheme for direct optical coupling of such a quantum dot with a diamond nitrogen-vacancy center at 637 nm.
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Submitted 26 March, 2009;
originally announced March 2009.