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Magneto-optical hologram lens with microsecond focal switching in magnetic garnet
Authors:
Hibiki Miyashita,
Toshiaki Watanabe,
Eri Negishi,
Mitsuteru Inoue,
Kazushi Ishiyama,
Taichi Goto
Abstract:
Active lenses based on metasurfaces have been demonstrated across broad applications, and their response speeds remain limited to the microsecond range. Here we report the experimental demonstration of a magneto-optical (MO) active lens based on a magnetic hologram formed on a magnetic garnet film. A Fresnel zone plate pattern was created using an array of permanent magnets, focusing a 633 nm lase…
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Active lenses based on metasurfaces have been demonstrated across broad applications, and their response speeds remain limited to the microsecond range. Here we report the experimental demonstration of a magneto-optical (MO) active lens based on a magnetic hologram formed on a magnetic garnet film. A Fresnel zone plate pattern was created using an array of permanent magnets, focusing a 633 nm laser beam of 12.5 mm diameter to a spot size of 0.7 mm at a focal length of 3.1 m with a modulation depth of ~91%. The focusing state was reversibly switched by applying an external magnetic field pulse. Through optimization of the magnetic field application system, a switching speed of 10.8 $μ$s was achieved, surpassing the operating speeds of conventional active lenses. The intrinsic picosecond-scale response of the MO effect indicates that further improvement in switching speed is achievable, establishing this work as a proof-of-concept for ultra-fast active lenses.
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Submitted 15 July, 2026;
originally announced July 2026.
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Induced nonlinear phase shift of forward volume spin waves in magnetic films and one-dimensional magnonic crystals
Authors:
Alexey B. Ustinov,
Roman V. Haponchyk,
Anton P. Burovikhin,
Mitsuteru Inoue,
Taichi Goto
Abstract:
A differential phase shift of a low-power spin wave (SW) induced by a high-power pumping wave co-propagating at different frequencies in perpendicularly magnetized magnetic films has been studied. We find that this effect for forward volume SWs propagating in yttrium iron garnet (YIG) films is stronger than that for surface SWs propagating in tangentially magnetized films. The results show that th…
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A differential phase shift of a low-power spin wave (SW) induced by a high-power pumping wave co-propagating at different frequencies in perpendicularly magnetized magnetic films has been studied. We find that this effect for forward volume SWs propagating in yttrium iron garnet (YIG) films is stronger than that for surface SWs propagating in tangentially magnetized films. The results show that the induced nonlinear phase shift up to 180° takes place for pumping wave power of a few milliwatts. The phenomenon paves the way for fast and energy-efficient control of one-dimensional magnon transport.
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Submitted 28 May, 2026;
originally announced May 2026.
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Mechanically exfoliated low-layered [Ca$_2$CoO$_3$]$_{0.62}$[CoO$_2$]: A single-crystalline p-type transparent conducting oxide
Authors:
Reiji Okada,
Hiroto Isomura,
Yoshiki J. Sato,
Ryuji Okazaki,
Masayuki Inoue,
Shinya Yoshioka
Abstract:
Transparent conducting oxides (TCOs) are essential components of optoelectronic devices and various materials have been explored for highly efficient TCOs having a combination of high transmittance and low sheet resistance. Here, we focus on a misfit thermoelectric oxide [Ca$_2$CoO$_3$]$_{0.62}$[CoO$_2$] and fabricate the transparent low-layered crystals by a mechanical tape-peeling method using t…
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Transparent conducting oxides (TCOs) are essential components of optoelectronic devices and various materials have been explored for highly efficient TCOs having a combination of high transmittance and low sheet resistance. Here, we focus on a misfit thermoelectric oxide [Ca$_2$CoO$_3$]$_{0.62}$[CoO$_2$] and fabricate the transparent low-layered crystals by a mechanical tape-peeling method using the single-crystalline samples. From the transmittance measurement, we find that the thickness of low-layered samples is several orders of hundred nanometers, which is comparable with the estimation from the scanning electron microscopy images. Compared to the previous results on the polycrystalline and $c$-axis oriented transparent films, the electrical resistivity is reduced owing to the single-crystalline nature. The figure of merit for the transparent conducting materials in the present low-layered samples is then evaluated to be higher than the values in the previous reports. The present results on the low-layered single-crystalline [Ca$_2$CoO$_3$]$_{0.62}$[CoO$_2$] may offer a unique class of multi-functional transparent thermoelectric oxides.
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Submitted 6 August, 2023;
originally announced August 2023.
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Absolute $\rm ^3$He polarimetry for a double-chambered cell using transmission of thermal neutrons
Authors:
A. Watanabe,
K. Sekiguchi,
T. Ino,
M. Inoue,
S. Nakai,
Y. Otake,
A. Taketani,
Y. Wakabayashi
Abstract:
We present an absolute $^3$He polarimetry method based on thermal neutron transmission for a double-chambered cell. This method utilizes the fact that a $^3$He nucleus has a large absorption cross section and a spin dependence for thermal neutrons. The cell had a pumping chamber and a target chamber. Polarized $^3$He gas was produced in the pumping chamber by SEOP and then diffused into the target…
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We present an absolute $^3$He polarimetry method based on thermal neutron transmission for a double-chambered cell. This method utilizes the fact that a $^3$He nucleus has a large absorption cross section and a spin dependence for thermal neutrons. The cell had a pumping chamber and a target chamber. Polarized $^3$He gas was produced in the pumping chamber by SEOP and then diffused into the target chamber. The $^3$He polarization in the target chamber was determined by comparing the neutron transmissions with the polarized and unpolarized targets. The measurement was performed at the RIKEN Accelerator-Driven Compact Neutron Source. The $^3$He polarization in the target chamber was determined with a statistical error of 1.8% and systematic uncertainty of 0.6%. This method can be used to obtain high-precision data of spin observables in few-nucleon scattering for the investigation of nuclear forces.
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Submitted 26 September, 2022;
originally announced September 2022.
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Entangled gene regulatory networks with cooperative expression endow robust adaptive responses to unforeseen environmental changes
Authors:
Masayo Inoue,
Kunihiko Kaneko
Abstract:
Living organisms must respond to environmental changes. Generally, accurate and rapid responses are provided by simple, unidirectional networks that connect inputs with outputs. Besides accuracy and speed, biological responses should also be robust to environmental or intracellular noise and mutations. Furthermore, cells must also respond to unforeseen environmental changes that have not previousl…
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Living organisms must respond to environmental changes. Generally, accurate and rapid responses are provided by simple, unidirectional networks that connect inputs with outputs. Besides accuracy and speed, biological responses should also be robust to environmental or intracellular noise and mutations. Furthermore, cells must also respond to unforeseen environmental changes that have not previously been experienced, to avoid extinction prior to the evolutionary rewiring of their networks, which takes numerous generations. We have investigated gene regulatory networks that mutually activate or inhibit, and have demonstrated that complex entangled networks can make appropriate input-output relationships that satisfy the robust and adaptive responses required for unforeseen challenges. Such entangled networks function for sloppy and unreliable responses with low Hill coefficient reactions for the expression of each gene. To compensate for such sloppiness, several detours in the regulatory network exist. By taking advantage of the averaging over such detours, the network shows a higher robustness to environmental and intracellular noise as well as to mutations in the network, when compared to simple unidirectional circuits. Furthermore, the appropriate response to unforeseen challenges, allowing for functional outputs, is achieved as many genes exhibit similar dynamic expression responses, irrespective of inputs, as confirmed by applying dynamic time warping and dynamic mode decomposition. As complex entangled networks are common in gene regulatory networks and global gene expression responses are observed in microbial experiments, the present results provide a novel design principle for cellular networks.
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Submitted 8 December, 2020;
originally announced December 2020.
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Spin Current Generation by a Surface Plasmon Polariton
Authors:
Theodorus Jonathan Wijaya,
Daigo Oue,
Mamoru Matsuo,
Yasutoshi Ito,
Kelvin Elphick,
Hironaga Uchida,
Mitsuteru Inoue,
Atsufumi Hirohata
Abstract:
Surface plasmon polariton (SPP) is an electromagnetic wave which is tightly localised beyond the diffraction limit at metallic surfaces. Recently, it is theoretically proposed that the angular momentum conversion between the SPP and electrons. In this work, we have successfully measured SPP induced spin currents, which proves the fact that the angular momenta are interconverted. Such conversion fr…
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Surface plasmon polariton (SPP) is an electromagnetic wave which is tightly localised beyond the diffraction limit at metallic surfaces. Recently, it is theoretically proposed that the angular momentum conversion between the SPP and electrons. In this work, we have successfully measured SPP induced spin currents, which proves the fact that the angular momenta are interconverted. Such conversion from light to a spin current can be used as a coupler in a next generation spintronic computing with optical data transfer or storage.
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Submitted 26 April, 2020;
originally announced April 2020.
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Joint Estimation of the Non-parametric Transitivity and Preferential Attachment Functions in Scientific Co-authorship Networks
Authors:
Masaaki Inoue,
Thong Pham,
Hidetoshi Shimodaira
Abstract:
We propose a statistical method to estimate simultaneously the non-parametric transitivity and preferential attachment functions in a growing network, in contrast to conventional methods that either estimate each function in isolation or assume some functional form for them. Our model is shown to be a good fit to two real-world co-authorship networks and be able to bring to light intriguing detail…
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We propose a statistical method to estimate simultaneously the non-parametric transitivity and preferential attachment functions in a growing network, in contrast to conventional methods that either estimate each function in isolation or assume some functional form for them. Our model is shown to be a good fit to two real-world co-authorship networks and be able to bring to light intriguing details of the preferential attachment and transitivity phenomena that would be unavailable under traditional methods. We also introduce a method to quantify the amount of contributions of those phenomena in the growth process of a network based on the probabilistic dynamic process induced by the model formula. Applying this method, we found that transitivity dominated PA in both co-authorship networks. This suggests the importance of indirect relations in scientific creative processes. The proposed methods are implemented in the R package FoFaF.
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Submitted 1 October, 2019;
originally announced October 2019.
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Cooperative reliable response from sloppy gene-expression dynamics
Authors:
Masayo Inoue,
Kunihiko Kaneko
Abstract:
Gene expression dynamics satisfying given input-output relationships were investigated by evolving the networks for an optimal response. We found three types of networks and corresponding dynamics, depending on the sensitivity of gene expression dynamics: direct response with straight paths, amplified response by a feed-forward network, and cooperative response with a complex network. When the sen…
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Gene expression dynamics satisfying given input-output relationships were investigated by evolving the networks for an optimal response. We found three types of networks and corresponding dynamics, depending on the sensitivity of gene expression dynamics: direct response with straight paths, amplified response by a feed-forward network, and cooperative response with a complex network. When the sensitivity of each gene's response is low and expression dynamics is sloppy, the last type is selected, in which many genes respond collectively to inputs, with local-excitation and global-inhibition structures. The result provides an insight into how a reliable response is achieved with unreliable units, and on why complex networks with many genes are adopted in cells.
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Submitted 3 June, 2018;
originally announced June 2018.
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Design of artificial genetic regulatory networks with multiple delayed adaptive responses
Authors:
Pablo Kaluza,
Masayo Inoue
Abstract:
Genetic regulatory networks with adaptive responses are widely studied in biology. Usually, models consisting only of a few nodes have been considered. They present one input receptor for activation and one output node where the adaptive response is computed. In this work, we design genetic regulatory networks with many receptors and many output nodes able to produce delayed adaptive responses. Th…
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Genetic regulatory networks with adaptive responses are widely studied in biology. Usually, models consisting only of a few nodes have been considered. They present one input receptor for activation and one output node where the adaptive response is computed. In this work, we design genetic regulatory networks with many receptors and many output nodes able to produce delayed adaptive responses. This design is performed by using an evolutionary algorithm of mutations and selections that minimizes an error function defined by the adaptive response in signal shapes. We present several examples of network constructions with a predefined required set of adaptive delayed responses. We show that an output node can have different kinds of responses as a function of the activated receptor. Additionally, complex network structures are presented since processing nodes can be involved in several input-output pathways.
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Submitted 2 June, 2016;
originally announced June 2016.
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Circuit architecture explains functional similarity of bacterial heat shock responses
Authors:
Masayo Inoue,
Namiko Mitarai,
Ala Trusina
Abstract:
Heat shock response is a stress response to temperature changes and a consecutive increase in amounts of unfolded proteins. To restore homeostasis, cells upregulate chaperones facilitating protein folding by means of transcription factors (TF). We here investigate two heat shock systems: one characteristic to gram negative bacteria, mediated by transcriptional activator sigma32 in E. coli, and ano…
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Heat shock response is a stress response to temperature changes and a consecutive increase in amounts of unfolded proteins. To restore homeostasis, cells upregulate chaperones facilitating protein folding by means of transcription factors (TF). We here investigate two heat shock systems: one characteristic to gram negative bacteria, mediated by transcriptional activator sigma32 in E. coli, and another characteristic to gram positive bacteria, mediated by transcriptional repressor HrcA in L. lactis. We construct simple mathematical model of the two systems focusing on the negative feedbacks, where free chaperons suppress sigma32 activation in the former, while they activate HrcA repression in the latter. We demonstrate that both systems, in spite of the difference at the TF regulation level, are capable of showing very similar heat shock dynamics. We find that differences in regulation impose distinct constrains on chaperone-TF binding affinities: the binding constant of free sigma32 to chaperon DnaK, known to be in 100 nM range, set the lower limit of amount of free chaperon that the system can sense the change at the heat shock, while the binding affinity of HrcA to chaperon GroE set the upper limit and have to be rather large extending into the micromolar range.
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Submitted 12 September, 2012;
originally announced September 2012.
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Type III Dyson Sphere of Highly Advanced Civilizations around a Super Massive Black Hole
Authors:
Makoto Inoue,
Hiromitsu Yokoo
Abstract:
We describe a new system for a society of highly advanced civilizations around a super massive black hole (SMBH), as an advanced Type III "Dyson Sphere", pointing out an efficient usage of energy for the advanced civilizations. SMBH also works as a sink for waste materials. Here we assume that Type III civilisations of Kardashev classification [1] form a galactic club [2] in a galaxy, and the ener…
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We describe a new system for a society of highly advanced civilizations around a super massive black hole (SMBH), as an advanced Type III "Dyson Sphere", pointing out an efficient usage of energy for the advanced civilizations. SMBH also works as a sink for waste materials. Here we assume that Type III civilisations of Kardashev classification [1] form a galactic club [2] in a galaxy, and the energy from the SMBH will be delivered to the club members, forming an energy control system similar to power grids in our present society. The energy is probably transmitted by a sharp beam with coherent electro-magnetic waves, which provide a new concept for the search for extraterrestrial intelligence (SETI) via detection of such energy transmission signals. This expands the search window for other intelligences within the Universe.
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Submitted 23 December, 2011;
originally announced December 2011.
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Weber's Law in Autocatalytic Reaction Networks
Authors:
Masayo Inoue,
Kunihiko Kaneko
Abstract:
Biological responses often obey Weber's law, according to which the magnitude of the response depends only on the fold change in the external input. In this study, we demonstrate that a system involving a simple autocatalytic reaction shows such response when a chemical is slowly synthesized by the reaction from a faster influx process. We also show that an autocatalytic reaction process occurring…
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Biological responses often obey Weber's law, according to which the magnitude of the response depends only on the fold change in the external input. In this study, we demonstrate that a system involving a simple autocatalytic reaction shows such response when a chemical is slowly synthesized by the reaction from a faster influx process. We also show that an autocatalytic reaction process occurring in series or in parallel can obey Weber's law with an oscillatory adaptive response. Considering the simplicity and ubiquity of the autocatalytic process, our proposed mechanism is thought to be commonly observed in biological reactions.
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Submitted 7 April, 2011;
originally announced April 2011.
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Dynamics of Coupled Adaptive Elements : Bursting and Intermittent Oscillations Generated by Frustration in Networks
Authors:
Masayo Inoue,
Kunihiko Kaneko
Abstract:
Adaptation to environmental change is a common property of biological systems. Cells initially respond to external changes in the environment, but after some time, they regain their original state. By considering an element consisting of two variables that show such adaptation dynamics, we studied a coupled dynamical system containing such elements to examine the diverse dynamics in the system a…
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Adaptation to environmental change is a common property of biological systems. Cells initially respond to external changes in the environment, but after some time, they regain their original state. By considering an element consisting of two variables that show such adaptation dynamics, we studied a coupled dynamical system containing such elements to examine the diverse dynamics in the system and classified the behaviors on the basis of the network structure that determined the interaction among elements. For a system with two elements, two types of behaviors, perfect adaptation and simple oscillation, were observed. For a system with three elements, in addition to these two types, novel types of dynamics, namely, rapid burst-type oscillation and a slow cycle, were discovered; depending on the initial conditions, these novel types of dynamics coexisted. These behaviors are a result of the characteristic dynamics of each element, i.e., fast response and slow adaptation processes. The behaviors depend on the network structure (in specific, a combination of positive or negative feedback among elements). Cooperativity among elements due to a positive feedback loop leads to simple oscillation, whereas frustration involving alternating positive and negative interactions among elements leads to the coexistence of rapid bursting oscillation and a slow cycle. These behaviors are classified on the basis of the frustration indices defined by the network structure. The period of the slow cycle is much longer than the original adaptation time scale, while the burst-type oscillation is a continued response that does not involve any adaptation. We briefly discuss the universal applicability of our results to a network of a larger number of elements and their possible relevance to biological systems.
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Submitted 14 July, 2009;
originally announced July 2009.
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Photonic band structure and eigenmodes of magnetophotonic crystals
Authors:
A. B. Khanikaev,
K. Yayoi,
M. J. Steel,
A. V. Baryshev,
M. Inoue
Abstract:
We study photonic band structure of two- and three-dimensional magnetophotonic crystals and the polarization properties of their eigenmodes using a plane wave expansion method. The alteration of the photonic band structure and eigenmodes by magnetization are examined. Two orientations are studied: in-plane magnetization and perpendicular magnetization. The magnetization-induced symmetry breaking…
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We study photonic band structure of two- and three-dimensional magnetophotonic crystals and the polarization properties of their eigenmodes using a plane wave expansion method. The alteration of the photonic band structure and eigenmodes by magnetization are examined. Two orientations are studied: in-plane magnetization and perpendicular magnetization. The magnetization-induced symmetry breaking effects are shown to be responsible for the formation of exotic magnetic Bloch modes, comprised of two or more coupled symmetric and antisymmetric Bloch modes of the corresponding non-magnetic photonic crystal. These results imply that uncoupled states of non-magnetic photonic crystals can be excited, or become coupled, in magnetic structures. We show that the polarization state of magnetic Bloch modes is very complicated. In the particular case of perpendicular to plane magnetization they represent in-plane elliptically (or even circularly) polarized waves with large longitudinal component.
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Submitted 6 July, 2009;
originally announced July 2009.
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Fano Resonance Between Mie and Bragg Scattering in Photonic Crystals
Authors:
M. V. Rybin,
A. B. Khanikaev,
M. Inoue,
K. B. Samusev,
M. J. Steel,
G. Yushin,
M. F. Limonov
Abstract:
We report the observation of a Fano resonance between continuum Mie scattering and a narrow Bragg band in synthetic opal photonic crystals. The resonance leads to a transmission spectrum exhibiting a Bragg dip with an asymmetric profile, which can be tunably reversed to a Bragg rise. The Fano asymmetry parameter is linked with the dielectric contrast between the permittivity of the filler and th…
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We report the observation of a Fano resonance between continuum Mie scattering and a narrow Bragg band in synthetic opal photonic crystals. The resonance leads to a transmission spectrum exhibiting a Bragg dip with an asymmetric profile, which can be tunably reversed to a Bragg rise. The Fano asymmetry parameter is linked with the dielectric contrast between the permittivity of the filler and the specific value determined by the opal matrix. The existence of the Fano resonance is directly related to disorder due to non-uniformity of a-SiO2 opal spheres. Proposed theoretical "quasi-3D" model produces results in excellent agreement with the experimental data.
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Submitted 23 February, 2009;
originally announced February 2009.
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Borrmann Effect in Photonic Crystals: Nonlinear Optical Consequences
Authors:
I. Razdolski,
T. Murzina,
O. Aktsipetrov,
M. Inoue
Abstract:
Nonlinear-optical manifestations of the Borrmann effect that are consequences of the spectral dependence of the spatial distributions of the electromagnetic field in a structure are observed in one-dimensional photonic crystals. The spectrum of the light self-focusing effect corresponding to the propagation-matrix calculations has been measured near the edge of the photonic gap.
Nonlinear-optical manifestations of the Borrmann effect that are consequences of the spectral dependence of the spatial distributions of the electromagnetic field in a structure are observed in one-dimensional photonic crystals. The spectrum of the light self-focusing effect corresponding to the propagation-matrix calculations has been measured near the edge of the photonic gap.
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Submitted 16 February, 2009;
originally announced February 2009.
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Third-order Self-action Effects in Photonic Microcavities
Authors:
I. Razdolski,
R. Kapra,
T. Murzina,
O. Aktsipetrov,
M. Inoue
Abstract:
Third-order nonlinear optical effects in photonic microcavities are studied. Significant light defocusing in the thin nonlinear microcavity spacer was observed. The polarization self-action effect was detected, when the large nonlinear polarization rotation angle arises when exciting the microcavity mode, being proportional to the radiation intensity.
Third-order nonlinear optical effects in photonic microcavities are studied. Significant light defocusing in the thin nonlinear microcavity spacer was observed. The polarization self-action effect was detected, when the large nonlinear polarization rotation angle arises when exciting the microcavity mode, being proportional to the radiation intensity.
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Submitted 16 February, 2009;
originally announced February 2009.
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High Power Model Fabrication of Biperiodic L-Support Disk-and-Washer Structure
Authors:
H. Ao,
Y. Iwashita,
T. Shirai,
A. Noda,
M. Inoue,
T. Kawakita,
K. Ohkubo,
K. Nakanishi
Abstract:
The high power test model of biperiodic L-support disk-and- washer was fabricated. Among some trouble in the fabrication, the main one was a vacuum leak in a brazing process. The repair test of the leak showed a good result; four units were recovered out of five leak units (recover rate 80%). While an accelerating mode frequency was tuned at an operating frequency of 2857 MHz by squeezing method…
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The high power test model of biperiodic L-support disk-and- washer was fabricated. Among some trouble in the fabrication, the main one was a vacuum leak in a brazing process. The repair test of the leak showed a good result; four units were recovered out of five leak units (recover rate 80%). While an accelerating mode frequency was tuned at an operating frequency of 2857 MHz by squeezing method, a coupling mode frequency of 2847MHz and the 3.4% field flatness (peak to peak ratio) were achieved.
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Submitted 23 August, 2000;
originally announced August 2000.
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Study of Multiple-Beam RFQ
Authors:
V. Kapin,
M. Inoue,
Y. Iwashita,
A. Noda
Abstract:
There are applications, which require MeV-range multiple-beams consisting of a large number of identical highly packed beamlets. The multiple-beam RFQ (MB-RFQ) arranged as a matrix array of longitudinal rod-electrodes is appropriate candidate. A configuration of MB-RFQ resonator should ensure identical quadrupole fields in every accelerating channel. The MB-RFQ resonators based on TEM transmissi…
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There are applications, which require MeV-range multiple-beams consisting of a large number of identical highly packed beamlets. The multiple-beam RFQ (MB-RFQ) arranged as a matrix array of longitudinal rod-electrodes is appropriate candidate. A configuration of MB-RFQ resonator should ensure identical quadrupole fields in every accelerating channel. The MB-RFQ resonators based on TEM transmission lines are studied. The resonators are designed by a periodical multiplication of a 4-rod unit cell in transverse direction. To understand fields of resonator the normal mode technique is applied. Novel configurations of MB-RFQ resonators based on these normal modes are generated. The RF properties of resonators are verified with computer simulations done with MAFIA code. Beam dynamics study for the initial 400-keV MB-RFQ has been performed using PARMTEQ code. The MB-RFQ parameters and the results of beam dynamics simulations are presented. The calculated beam transmission is 33% at injection of 50-keV, 20mA deuteron beam.
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Submitted 13 May, 1999;
originally announced May 1999.