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Resonance effects due to the excitation of surface Josephson plasma waves in layered superconductors

Physical Review B 2009年第21期79卷 214501-214501页

作者： V. A. Yampol’skii A. V. Kats M. L. Nesterov A. Yu. Nikitin T. M. Slipchenko Sergey Savel’ev Franco Nori Advanced Science Institute The Institute of Physical and Chemical Research (RIKEN) Wako-shi Saitama 351-0198 Japan A.Ya. Usikov Institute for Radiophysics and Electronics Ukrainian Academy of Sciences 61085 Kharkov Ukraine Department of Physics Loughborough University Loughborough LE11 3TU United Kingdom Department of Physics Center for Theoretical Physics Applied Physics Program Center for the Study of Complex Systems University of Michigan Ann Arbor Michigan 48109-1040 USA

We analytically examine the excitation of surface Josephson plasma waves (SJPWs) in layered superconductors by an incident electromagnetic wave. The mechanism of excitation is related to the diffraction of the incident wave due to a small periodic modulation in the ab plane of the maximum c-axis Josephson current density. We show that the absorption of the incident wave can be substantially increased, for certain incident angles, due to the resonance excitation of SJPWs. The absorption increase is accompanied by a decrease in the specular reflection. Moreover, we find the dependence of the resonance value of the incident angle on the parameters of the superconductor and the frequency of the incident wave, and the depth of the modulations guaranteeing the total absorption (and total suppression of the specular reflection). Numerical examples of the resonance effects are presented for Bi2212 superconductors.

关键词： bismuth compounds calcium current density electromagnetic wave absorption electromagnetic wave diffraction high-temperature superconductors Josephson effect resonance solid-state plasma strontium compounds

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Nonlinear electrodynamics in layered superconductors

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Physical Review B 2008年第2期78卷 024511-024511页

作者： V. A. Yampol’skii Sergey Savel’ev A. L. Rakhmanov Franco Nori Advanced Science Institute The Institute of Physical and Chemical Research (RIKEN) Wako-shi Saitama 351-0198 Japan A. Ya. Usikov Institute for Radiophysics and Electronics Ukrainian Academy of Sciences 61085 Kharkov Ukraine Department of Physics Loughborough University Loughborough LE11 3TU United Kingdom Institute for Theoretical and Applied Electrodynamics Russian Academy of Sciences 125412 Moscow Russia Department of Physics Center for Theoretical Physics Applied Physics Program Center for the Study of Complex Systems The University of Michigan Ann Arbor Michigan 48109-1040 USA

We analyze theoretically the effect of a weak nonlinearity on the propagation of Josephson plasma waves in layered superconductors. The nonlinearity originates from the Josephson relation between the current density across superconducting layers and gauge-invariant phase difference of the order parameter. We show that strong nonlinear effects can be observed for electromagnetic waves with frequency slightly above or slightly below the plasma frequency. We study the nonlinear plasma resonance accompanied by the hysteretic dependence of the wave amplitude on the frequency. This hysteresis transforms the continuous terahertz radiation into a series of short electromagnetic high-amplitude pulses. We also consider the propagation of a nonlinear terahertz beam localized in the direction across the superconducting layers. This phenomenon is an analog of the self-focusing effect in nonlinear optics. The nonlinear phenomena in layered superconductors considered here can be potentially useful for the design of a new generation of terahertz devices.

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Hysteretic jumps in the response of layered superconductors to electromagnetic fields

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Physical Review B 2008年第18期78卷 184504-184504页

作者： V. A. Yampol’skii T. M. Slipchenko Z. A. Mayzelis D. V. Kadygrob S. S. Apostolov S. E. Savel’ev Franco Nori Advanced Science Institute The Institute of Physical and Chemical Research (RIKEN) Wako-shi Saitama 351-0198 Japan A. Ya. Usikov Institute for Radiophysics and Electronics Ukrainian Academy of Sciences 61085 Kharkov Ukraine V. N. Karazin Kharkov National University 61077 Kharkov Ukraine Department of Physics Loughborough University Loughborough LE11 3TU United Kingdom Department of Physics Center for Theoretical Physics Applied Physics Program Center for the Study of Complex Systems University of Michigan Ann Arbor Michigan 48109-1040 USA

We consider here a layered superconductor subject to an externally applied moderately strong electromagnetic field. We predict hysteretic jumps in the dependence of the surface reactance of the superconductor on the amplitude H0 of the incident electromagnetic wave. This very unusual nonlinear phenomenon can be observed in thin superconducting slabs at not very strong ac amplitudes if the frequency of the irradiating field is close to the Josephson plasma frequency. Using the set of coupled sine-Gordon equations, we derive the expression for the phase shift χ of the reflected wave and obtain the conditions for the appearance of hysteresis in the χ(H0) dependence.

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Topological Edge State Nucleation in Frequency Space and its Realization with Floquet Electrical Circuits

arXiv

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arXiv 2024年

作者： Stegmaier, Alexander Fritzsche, Alexander Sorbello, Riccardo Greiter, Martin Brand, Hauke Barko, Christine Hofer, Maximilian Schwingenschlögl, Udo Moessner, Roderich Lee, Ching Hua Szameit, Alexander Alù, Andrea Kießling, Tobias Thomale, Ronny Institute for Theoretical Physics and Astrophysics University of Würzburg Am Hubland WürzburgD-97074 Germany Physikalisches Institut Röntgen Research Center for Complex Material Systems Universität Würzburg WürzburgD-97074 Germany Thuwal23955 Saudi Arabia Max Planck Institute for the Physics of Complex Systems Nöthnitzer Straße 38 Dresden01187 Germany Würzburg-Dresden Cluster of Excellence ct.qmat WürzburgD-97074 Germany Department of Physics National University of Singapore Singapore117542 Singapore Institute of Physics University of Rostock Rostock Germany Photonics Initiative Advanced Science Research Center City University of New York New YorkNY10031 United States Physics Program Graduate Center City University of New York New YorkNY10016 United States

We build Floquet-driven capactive circuit networks to realize topological states of matter in the frequency domain. We find the Floquet circuit network equations of motion to reveal a potential barrier which effectively acts as a boundary in frequency space. By implementing a Su-Shrieffer-Heeger Floquet lattice model and measuring the associated circuit Laplacian and characteristic resonances, we demonstrate how topological edge modes can nucleate at such a frequency boundary. © 2024, CC BY.

关键词： Equations of motion

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On the Minimal Theory of Consciousness Implicit in Active Inference

arXiv

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arXiv 2024年

作者： Whyte, Christopher J. Corcoran, Andrew W. Robinson, Jonathan Smith, Ryan Moran, Rosalyn J. Parr, Thomas Friston, Karl J. Seth, Anil K. Hohwy, Jakob Monash Centre for Consciousness & Contemplative Studies Monash University Melbourne Australia Brain and Mind Centre University of Sydney Sydney Australia Centre for Complex Systems University of Sydney Sydney Australia Laureate Institute for Brain Research TulsaOK United States Department of Neuroimaging King's College London London United Kingdom Nuffield Department of Clinical Neurosciences University of Oxford Oxford United Kingdom Queen Square Institute of Neurology University College London United Kingdom Sussex Centre for Consciousness Science Department of Informatics University of Sussex Brighton United Kingdom Program on Brain Mind and Consciousness Canadian Institute for Advanced Research Toronto Canada

The multifaceted nature of experience poses a challenge to the study of consciousness. Traditional neuroscientific approaches often concentrate on isolated facets, such as perceptual awareness or the global state of consciousness and construct a theory around the relevant empirical paradigms and findings. Theories of consciousness are, therefore, often difficult to compare;indeed, there might be little overlap in the phenomena such theories aim to explain. Here, we take a different approach: starting with active inference, a first principles framework for modelling behaviour as (approximate) Bayesian inference, and building up to a minimal theory of consciousness, which emerges from the shared features of computational models derived under active inference. We review a body of work applying active inference models to the study of consciousness and argue that there is implicit in all these models a small set of theoretical commitments that point to a minimal (and testable) theory of consciousness. © 2024, CC BY.

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Honeycomb-Lattice Mott Insulator on Tantalum Disulphide

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Physical Review Letters 2020年第9期125卷 096403-096403页

作者： Jinwon Lee Kyung-Hwan Jin Andrei Catuneanu Ara Go Jiwon Jung Choongjae Won Sang-Wook Cheong Jaeyoung Kim Feng Liu Hae-Young Kee Han Woong Yeom Center for Artificial Low Dimensional Electronic Systems Institute for Basic Science (IBS) Pohang 37673 Republic of Korea Department of Physics Pohang University of Science and Technology Pohang 37673 Republic of Korea Department of Materials Science and Engineering University of Utah Salt Lake City Utah 84112 United States Department of Physics University of Toronto Ontario M5S 1A7 Canada Center for Theoretical Physics of Complex Systems Institute for Basic Science (IBS) Daejeon 34126 Republic of Korea Laboratory for Pohang Emergent Materials Pohang University of Science and Technology Pohang 37673 Republic of Korea Rutgers Center for Emergent Materials and Department of Physics and Astronomy Rutgers University Piscataway New Jersey 08854 United States Canadian Institute for Advanced Research CIFAR Program in Quantum Materials Toronto Ontario M5G 1M1 Canada

Effects of electron many-body interactions amplify in an electronic system with a narrow bandwidth opening a way to exotic physics. A narrow band in a two-dimensional (2D) honeycomb lattice is particularly intriguing as combined with Dirac bands and topological properties but the material realization of a strongly interacting honeycomb lattice described by the Kane-Mele-Hubbard model has not been identified. Here we report a novel approach to realize a 2D honeycomb-lattice narrow-band system with strongly interacting 5d electrons. We engineer a well-known triangular lattice 2D Mott insulator 1T−TaS2 into a honeycomb lattice utilizing an adsorbate superstructure. Potassium (K) adatoms at an optimum coverage deplete one-third of the unpaired d electrons and the remaining electrons form a honeycomb lattice with a very small hopping. Ab initio calculations show extremely narrow Z2 topological bands mimicking the Kane-Mele model. Electron spectroscopy detects an order of magnitude bigger charge gap confirming the substantial electron correlation as confirmed by dynamical mean field theory. It could be the first artificial Mott insulator with a finite spin Chern number.

关键词： Adsorption Topological materials Mott insulators Transition metal dichalcogenides Electron-correlation calculations Scanning tunneling microscopy

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USING VIRTUAL ENVIRONMENTS IN THE DESIGN OF SHIPS

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NAVAL ENGINEERS JOURNAL 1994年第3期106卷 91-106页

作者： JONS, OP RYAN, JC JONES, GW Otto P. Jons:received a Diplom Ing. in shipbuilding from the Technical University of Hanover W. Germany and an MS in naval architecture and marine engineering from MIT. He then joined Litton Ship Systems where he was responsible for the preliminary design of the DD-963 hull structure and then for ship system integration as manager LHA ship systems engineering department. From 1972 to 1974 he was the principal research scientist at Hydronautics. In 1974 as technical director he helped establish the Crystal City office of Designers and Planners. Mr. Jons was one of the co-founders of Advanced Marine Enterprises Inc. in 1976 where he serves as corporate vice president engineering. J. Christopher Ryan:earned his bachelors and masters degrees in naval architecture from Webb Institute and MIT respectively. He spent three years at the advanced marine technology division of Litton Industries working on the DD-963 class ship design and related computer aided design projects. He subsequently went to the Navy Department concentrating on early stage design of surface combatants for twelve years including work on the FFG-7 Sea Control Ship CSGN and CVV aircraft carrier projects. He then shifted focus and became the Technical Director for the Computer Supported Design Program in NavSea for five years. Mr. Ryan has served in several supervisory positions within the Ship Design Group in NavSea since that time. He is currently the director of the future ship concepts division. Gary W. Jones:graduated from the University of Tennessee in 1971 with a BS in mechanical engineering and followed up with graduate work at George Washington University and the University of Maryland. Mr. Jones was with the Naval Sea Systems Command from 1971 until 1988 where he was a naval architect in the submarine section of the hull form design division. In 1988 he was detailed to the Defense Advanced Research Projects Agency (DARPA) where he became the program manager for the advanced submarine technology program's hydrodynamic hydroac

A major contributor to the expense and length of time to design, build, and test new systems has been the need to build and test hardware prototypes to determine their effectiveness in meeting operational requirements. Recent and dramatic advances in computer simulation technologies hold forth the promise of revolutionizing design and acquisition strategies by providing the means to validate end users' requirements prior to hardware construction. By designing and operationally testing virtual prototypes in a virtual environment, these technologies will soon offer naval architects the ability to build and launch ships in computer-based cyberspace in lieu of the shipbuilder's ways. The authors of this paper provide the background for these developments, explore the significance and ramifications of these technologies to the current process of ship and system design, outline challenges lying ahead, and present their vision and recommendations for future development.

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Breathing chromium spinels: a showcase for a variety of pyrochlore Heisenberg Hamiltonians

arXiv

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arXiv 2019年

作者： Ghosh, Pratyay Iqbal, Yasir Müller, Tobias Ponnaganti, Ravi T. Thomale, Ronny Narayanan, Rajesh Reuther, Johannes Gingras, Michel J.P. Jeschke, Harald O. Department of Physics Indian Institute of Technology Madras Chennai600036 India Institute for Theoretical Physics and Astrophysics Julius-Maximilians-Universität Würzburg Am Hubland Würzburg97074 Germany Dahlem Center for Complex Quantum Systems Fachbereich Physik Freie Universität Berlin Berlin14195 Germany Department of Physics and Astronomy University of Waterloo WaterlooONN2L 3G1 Canada Quantum Materials Program Canadian Institute for Advanced Research MaRS Centre West Tower 661 University Ave. Suite 505 TorontoONM5G 1M1 Canada Research Institute for Interdisciplinary Science Okayama University Okayama700-8530 Japan

We address the long-standing problem of the microscopic origin of the richly diverse phenomena in the chromium breathing pyrochlore material family. Combining electronic structure and renormalization group techniques we resolve the magnetic interactions and analyze their reciprocal-space susceptibility. We show that the physics of these materials is principally governed by long-range Heisenberg Hamiltonian interactions, a hitherto unappreciated fact. Our calculations uncover that in these isostructural compounds, the choice of chalcogen triggers a proximity of the materials to classical spin liquids featuring degenerate manifolds of wave-vectors of different dimensions: A Coulomb phase with three-dimensional degeneracy for LiInCr4O8 and LiGaCr4O8, a spiral spin liquid with two-dimensional degeneracy for CuInCr4Se8 and one-dimensional line degeneracies characteristic of the face-centered cubic antiferromagnet for LiInCr4S8, LiGaCr4S8 and CuInCr4S8. The surprisingly complex array of prototypical pyrochlore behaviors we discovered in chromium spinels may inspire studies of transition paths between different semi-classical spin liquids by doping or pressure. Copyright © 2019, The Authors. All rights reserved.

关键词： Lithium compounds

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Affordability, logistics R&D and fleet systems

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NAVAL ENGINEERS JOURNAL 1996年第3期108卷 199-213页

作者： Schulte, DP Skolnick, A He has supported the development and operation of several naval systems including advanced component selection for Trident II fire control and navigation systems. He served as branch manager of the Surface Ship ASW Combat System Branch which acted as the acquisition engineering agent for the AN/SQQ-89 Surface Ship Anti-Submarine Warfare Weapon System. He was then selected to manage the Module Engineering Department which provided engineering support to numerous naval systems including the AN/BSY-1 Submarine Combat System and the Trident II fire control and navigation system. He then served as the deputy program manager for NAVSEA Progressive Maintenance (2M/ATE). He holds a B.S. degree in Electrical Engineering from Purdue University and currently is pursuing a Maste's degree in Public Environmental Affairs at Indiana University—Purdue University Indianapolis. He served at Applied Physics Laboratory/The Johns Hopkins University in missile development then aboard USS Boston (CAG-1) and played leading roles in several weapon system developments (Regulus Terrier Tartar Talos) inertial navigation (Polaris) deep submergence (DSRV) and advanced ship designs (SES). He later was director Combat System Integration Naval Sea Systems Command and head Combat Projects Naval Ship Engineering Center. He led the Navy's High Energy Lasers and Directed Energy Weapons development efforts. He was vice president advanced technology at Operations Research Inc. and vice president maritime engineering at Defense Group Inc. before starting SSC in 1991. Dr. Skolnick holds a B.S. degree in Mathematics and Economics Queens College an M.A. degree in Mathematics and Philosophy Columbia University an M.S. degree in Electrical/Aeronautical Engineering U.S. Naval Postgraduate School and a Ph.D. in Electrical Engineering and Applied Mathematics from Polytechnic University in New York. He is the author of many published papers on engineering design issues source selection procedures and large-scale complex technology problems

The Fleet continues to require high performance systems that can operate with dependability in the seas' unforgiving environments and under hostile action. Those demands are not new. What has changed is the urgent priority formerly assigned to national defense issues. The arguments for continued superpower military strength are now roiled in politics along with unsettled budgets and uncertain force level projections. Current expectations revolve about indefinite fiscal and operational issues (difficult funding constraints and broadband threats). In the actual event of ''doing more with less,'' a practical response is to apply the creative power available from sound engineering judgement and the crucible of experience to the immediate needs of the Fleet. The attempt to shorten the path between advanced development effort and Fleet use has been tried occasionally in the past, often, without exemplary results. The Sustainable Hardware and Affordable Readiness Practices (SHARP) program, is a generic R&D effort under OpNav sponsorship that has been working steadily on sensible solutions to product engineering problems. Armed today with fast-time, large-scale computation abilities and modern tools for technical problem solving coupled with specialized engineering knowledge, it has been refreshed and is underway satisfying existing Fleet needs. The relationship between fully responsive engineering services and current operational needs is always demanding. The connection between advanced engineering development (6.3 category funds) and immediate Fleet usage brings added complexity and challenge, both technical and organizational. Illustrative examples of affordable engineering solutions to ''retain, revise, replace or retire'' questions are presented within the context of both Fleet realities and budgetary limitations. The discussion covers legacy system support, civil/military considerations and Fleet maintenance issues. It describes the substantial and critical payoffs i

关键词： Warships

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Quantum chaos and critical behavior on a chip

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Physical Review B 2009年第16期80卷 165308-165308页

作者： Neill Lambert Yueh-nan Chen Robert Johansson Franco Nori Advanced Science Institute The Institute of Physical and Chemical Research (RIKEN) Saitama 351-0198 Japan Department of Physics and National Center for Theoretical Sciences National Cheng-Kung University Tainan 701 Taiwan Center for Theoretical Physics Physics Department Applied Physics Program Center for the Study of Complex Systems The University of Michigan Ann Arbor Michigan 48109-1040 USA

The Dicke model describes N qubits (or two-level atoms) homogeneously coupled to a bosonic mode. Here we examine an open-system realization of the Dicke model, which contains critical and chaotic behaviors. In particular, we extend this model to include an additional open transport qubit (coupled to the bosonic mode) for passive and active measurements. We illustrate how the scaling (in the number of qubits N) of the super-radiant phase transition can be observed in both current and current-noise measurements through the transport qubit. Using a master equation, we also investigate how the phase transition is affected by the back action from the transport qubit and losses in the cavity. In addition, we show that the nonintegrable quantum chaotic character of the Dicke model is retained in an open-system environment. We propose how all of these effects could been seen in a circuit-QED system formed from an array of superconducting qubits, or an atom chip, coupled to a quantized resonant cavity (e.g., a microwave transmission line).

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