cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Quantum field theory of the Casimir force for graphene
Creators: name: Klimchitskaya, G. L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present theoretical description of the Casimir interaction in graphene systems which is based on the Lifshitz theory of dispersion forces and the formalism of the polarization tensor in (2+1)-dimensional space-time. The representation for the polarization tensor of graphene allowing the analytic continuation to the whole plane of complex frequencies is given. This representation is used to obtain simple asymptotic expressions for the reflection coefficients at all Matsubara frequencies and to investigate the origin of large thermal effect in the Casimir force for graphene. The developed theory is shown to be in a good agreement with the experimental data on measuring the gradient of the Casimir force between a Au-coated sphere and a graphene-coated substrate. The possibility to observe the thermal effect for graphene due to a minor modification of the already existing experimental setup is demonstrated.
description: 13 pages, 4 figures
Non-Gaussian fluctuation dynamics in relativistic fluids
Creators: name: An, Xin
name: Basar, Gokce
name: Stephanov, Mikhail
name: Yee, Ho-Ung
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We consider non-equilibrium evolution of non-Gaussian fluctuations within relativistic hydrodynamics relevant for the QCD critical point search in heavy-ion collision experiments. We rely on the hierarchy of relaxation time scales, which emerges in the hydrodynamic regime near the critical point, to focus on the slowest mode such as the fluctuations of specific entropy, whose equilibrium magnitude, non-Gaussianity and typical relaxation time are increasing as the critical point is approached. We derive evolution equations for the non-Gaussian correlators of this diffusive mode in an arbitrary relativistic hydrodynamic flow. We compare with the simpler case of the stochastic diffusion on a static homogeneous background and identify terms which are specific to the case of the full hydrodynamics with pressure fluctuations and flow.
description: 29 pages, 8 figures. Version accepted by PRC
A Comparative Study of Four-year and Community College Students’ Subjective Experiences of Emerging Adulthood, The Need to Belong, and Well-being
Creators: name: McCoy, Shelly
name: Chou, Catherine P.
name: Grahe, Jon
name: Miller, Travis
Publisher: name: Open Science Framework
Year: 2022

description: A Comparative Study of Four-year and Community College Students’ Subjective Experiences of Emerging Adulthood, The Need to Belong, and Well-being. This project includes data and supplemental analyses associated with this publication
Galaxy structure from multiple tracers: II. M87 from parsec to megaparsec scales
Creators: name: Oldham, L. J.
name: Auger, M. W.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Following a number of conflicting studies of M87's mass profile, we undertake a dynamical analysis of multiple tracer populations to constrain its mass over a large radius range. We combine stellar kinematics in the central regions with the dynamics of 612 globular clusters out to 200 kpc and satellite galaxies extending to scales comparable with the virial radius. Using a spherical Jeans analysis, we are able to disentangle the mass contributions from the dark and baryonic components and set constraints on the structure of each. Assuming isotropy, we explore four different models for the dark matter halo and find that a centrally-cored dark matter distribution is preferred. We infer a stellar mass-to-light ratio $Υ_{\star,v} = 6.9 \pm 0.1$ -- consistent with a Salpeter-like IMF -- and a core radius $r_c = 67 \pm 20$ kpc. We then introduce anisotropy and find that, while the halo remains clearly cored, the radial stellar anisotropy has a strong impact on both $Υ_{\star,v}$ and the core's radius; here we find $Υ_{\star,v} = 3.50_{-0.36}^{+0.32}$ -- consistent with a Chabrier-like IMF -- and $r_c = 19.00_{-8.34}^{+8.38}$ kpc. Thus the presence of a core at the centre of the dark halo is robust against anisotropy assumptions, while the stellar mass and core size are not. We are able to reconcile previously discrepant studies by showing that modelling the globular cluster data alone leads to the very different inference of a super-NFW cusp, thus highlighting the value of multiple-population modelling, and we point to the possible role of M87's AGN and the cluster environment in forming the central dark matter core.
description: 24 pages, 17 figures; accepted for publication in MNRAS
Effect of phase and time coupling on NMR relaxation rate by random walk in phase space
Creators: name: Lin, Guoxing
Publisher: name: arXiv
Year: 2023
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The phase time coupling effect on NMR relaxation is investigated based on coupled and uncoupled phase diffusion. The results indicate that phase and time coupling could significantly impact the NMR relaxation time. The spectral density term in the relaxation time expression is modified with an apparent angular frequency, which could be twice the conventional angular frequency when the phase-time coupling is strong. A phase-time coupling constant is proposed to modify the conventional angular frequency to the apparent angular frequency. The modified NMR relaxation time can successfully fit the experimental data taken from Ref. [6]. The results could improve our understanding and analysis of NMR relaxation.
description: 21 pages, 3 figures
Asynchronous Deep Double Duelling Q-Learning for Trading-Signal Execution in Limit Order Book Markets
Creators: name: Nagy, Peer
name: Calliess, Jan-Peter
name: Zohren, Stefan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Trading and Market Microstructure (q-fin.TR)
subject: Machine Learning (cs.LG)
subject: FOS: Economics and business
subject: FOS: Computer and information sciences

description: We employ deep reinforcement learning (RL) to train an agent to successfully translate a high-frequency trading signal into a trading strategy that places individual limit orders. Based on the ABIDES limit order book simulator, we build a reinforcement learning OpenAI gym environment and utilise it to simulate a realistic trading environment for NASDAQ equities based on historic order book messages. To train a trading agent that learns to maximise its trading return in this environment, we use Deep Duelling Double Q-learning with the APEX (asynchronous prioritised experience replay) architecture. The agent observes the current limit order book state, its recent history, and a short-term directional forecast. To investigate the performance of RL for adaptive trading independently from a concrete forecasting algorithm, we study the performance of our approach utilising synthetic alpha signals obtained by perturbing forward-looking returns with varying levels of noise. Here, we find that the RL agent learns an effective trading strategy for inventory management and order placing that outperforms a heuristic benchmark trading strategy having access to the same signal.
Sensing rotations with multiplane light conversion
Creators: name: Eriksson, M.
name: Goldberg, A. Z.
name: Hiekkamäki, M.
name: Bouchard, F.
name: Leuchs, G.
name: Fickler, R.
name: Sanchez-Soto, L. L.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We report an experiment estimating the three parameters of a general rotation. The scheme uses quantum states attaining the ultimate precision dictated by the quantum Cramér-Rao bound. We realize the states experimentally using the orbital angular momentum of light and implement the rotations with a multiplane light conversion setup, which allows one to perform arbitrary unitary transformations on a finite set of spatial modes. The observed performance suggests a range of potential applications in the next generation of rotation sensors.
description: 8 pages, 4 figures. Comments welcome! arXiv admin note: text overlap with arXiv:2012.00590
Distributed robust estimation over randomly switching networks using $H_\infty$ consensus
Creators: name: Ugrinovskii, V.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: The paper considers a distributed robust estimation problem over a network with Markovian randomly varying topology. The objective is to deal with network variations locally, by switching observer gains at affected nodes only. We propose sufficient conditions which guarantee a suboptimal $H_\infty$ level of relative disagreement of estimates in such observer networks. When the status of the network is known globally, these sufficient conditions enable the network gains to be computed by solving certain LMIs. When the nodes are to rely on a locally available information about the network topology, additional rank constraints are used to condition the gains, given this information. The results are complemented by necessary conditions which relate properties of the interconnection graph Laplacian to the mean-square detectability of the plant through measurement and interconnection channels.
Stochastic and Mixed Density Functional Theory within the projector augmented wave formalism for the simulation of warm dense matter
Creators: name: Sharma, Vidushi
name: Collins, Lee A.
name: White, Alexander J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Stochastic and mixed stochastic-deterministic density functional theory (DFT) are promising new approaches for the calculation of the equation-of-state and transport properties in materials under extreme conditions. In the intermediate warm dense matter regime, a state between correlated condensed matter and kinetic plasma, electrons can range from being highly localized around nuclei to delocalized over the whole simulation cell. The plane-wave basis pseudo-potential approach is thus the typical tool of choice for modeling such systems at the DFT level. Unfortunately, the stochastic DFT methods scale as the square of the maximum plane-wave energy in this basis. To reduce the effect of this scaling, and improve the overall description of the electrons within the pseudo-potential approximation, we present stochastic and mixed DFT developed and implemented within the projector augmented wave formalism. We compare results between the different DFT approaches for both single-point and molecular dynamics trajectories and present calculations of self-diffusion coefficients of solid density carbon from 1 to 50 eV.
Understanding Bio-Nano Interactions in Alzheimer’s Disease and Cancer
Creators: name: NANDAKUMAR, APARNA
Publisher: name: Monash University
Year: 2023
Subjects: classificationCode: 310205
subject: Proteomics and metabolomics
classificationCode: 320604
subject: Nanomedicine

description: With the increasing application of nanomedicine, it is essential to have an in-depth understanding of the interaction between nanoparticles (NPs) and biomacromolecules, especially blood proteins to unravel the behaviour of NPs in a complex biological milieu. My research aims to evaluate the protein coronas of both naturally occurring nanomaterials (amyloid fibrils) and engineered nanomaterials, (gold nanoparticles) to comprehensively understand the factors influencing the formation of plasma protein coronas, their composition, and their cellular outcomes, where the findings implicated the role of protein corona of amyloid fibrils in hindering the immune recognition of Aβ amyloid fibrils and their cross seeding with IAPP and in the modulating the paracellular pathway associated with gold nanomaterials.
Quality Indicators for Preference-based Evolutionary Multi-objective Optimization Using a Reference Point: A Review and Analysis
Creators: name: Tanabe, Ryoji
name: Li, Ke
Publisher: name: arXiv
Year: 2023
Subjects: subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences

description: Some quality indicators have been proposed for benchmarking preference-based evolutionary multi-objective optimization algorithms using a reference point. Although a systematic review and analysis of the quality indicators are helpful for both benchmarking and practical decision-making, neither has been conducted. In this context, first, this paper reviews existing regions of interest and quality indicators for preference-based evolutionary multi-objective optimization using the reference point. We point out that each quality indicator was designed for a different region of interest. Then, this paper investigates the properties of the quality indicators. We demonstrate that an achievement scalarizing function value is not always consistent with the distance from a solution to the reference point in the objective space. We observe that the regions of interest can be significantly different depending on the position of the reference point and the shape of the Pareto front. We identify undesirable properties of some quality indicators. We also show that the ranking of preference-based evolutionary multi-objective optimization algorithms depends on the choice of quality indicators.
description: This is an accepted version of a paper published in the IEEE Transactions on Evolutionary Computation
Progress in constraining axion and non-Newtonian gravity from the Casimir effect
Creators: name: Mostepanenko, V. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We consider recent progress in constraining the axion-nucleon coupling constants and the Yukawa-type corrections to Newtonian gravity from experiments on measuring the Casimir interaction. After a brief review of previously obtained constraints, we concentrate on the new Casimir-less experiment, which allows to strengthen the known results up to factors of 60 and 1000 for the axion-like particles and Yukawa-type corrections, respectively. We also discuss possibilities allowing to further strengthen the constraints on axion-nucleon coupling constants, and propose a new experiment aiming to achieve this goal.
description: 14 pages, 2 figures
Temperature Dependent Photophysics of Single NV Centers in Diamond
Creators: name: Happacher, Jodok
name: Bocquel, Juanita
name: Dinani, Hossein T.
name: Tschudin, Märta A.
name: Reiser, Patrick
name: Broadway, David A.
name: Maze, Jeronimo R.
name: Maletinsky, Patrick
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a comprehensive study of the temperature and magnetic-field dependent photoluminescence (PL) of individual NV centers in diamond, spanning the temperature-range from cryogenic to ambient conditions. We directly observe the emergence of the NV's room-temperature effective excited state structure and provide a clear explanation for a previously poorly understood broad quenching of NV PL at intermediate temperatures around 50 K. We develop a model that quantitatively explains all of our findings, including the strong impact that strain has on the temperaturedependence of the NV's PL. These results complete our understanding of orbital averaging in the NV excited state and have significant implications for the fundamental understanding of the NV center and its applications in quantum sensing.
description: 5 pages, 4 figures plus Supplementary Material. Questions and comments are welcome. arXiv admin note: text overlap with arXiv:2105.08075
Multiplicity of solutions to a nonlinear elliptic problem on a Riemannian orbifold
Creators: name: Ramos, Gustavo de Paula
Publisher: name: arXiv
Year: 2023
Subjects: subject: Analysis of PDEs (math.AP)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 35J60, 35B25, 35J20, 58E05

description: We employ the photography method to obtain a lower bound for the number of solutions to a nonlinear elliptic problem on a Riemannian orbifold in function of the Lusternik--Schnirelmann category of its submanifold of points with largest local group.
description: 23 pages; comments are welcome
Kinematical properties of coronal mass ejections
Creators: name: Temmer, Manuela
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Coronal mass ejections (CMEs) are the most dynamic phenomena in our solar system. They abruptly disrupt the continuous outflow of solar wind by expelling huge clouds of magnetized plasma into interplanetary space with velocities enabling to cross the Sun-Earth distance within a few days. Earth-directed CMEs may cause severe geomagnetic storms when their embedded magnetic fields and the shocks ahead compress and reconnect with the Earth's magnetic field. The transit times and impacts in detail depend on the initial CME velocity, size, and mass, as well as on the conditions and coupling processes with the ambient solar wind flow in interplanetary space. The observed CME parameters may be severly affected by projection effects and the constant changing environmental conditions are hard to derive. This makes it difficult to fully understand the physics behind CME evolution, preventing to do a reliable forecast of Earth-directed events. This short review focusing on observational data, shows recent methods which were developed to derive the CME kinematical profile for the entire Sun-Earth distance range as well as studies which were performed to shed light on the physical processes that CMEs encounter when propagating from Sun to Earth.
description: accepted for publication in Astronomische Nachrichten
Quantum computation at the edge of a disordered Kitaev honeycomb lattice
Creators: name: Timoshuk, Igor
name: Tikhonov, Konstantin
name: Makhlin, Yuriy
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We analyze propagation of quantum information along chiral Majorana edge states in two-dimensional topological materials. The use of edge states may facilitate the braiding operation, an important ingredient in topological quantum computations. For the edge of the Kitaev honeycomb model in a topological phase, we discuss how the edge states can participate in quantum-information processing, and consider a two-qubit logic gate between distant external qubits coupled to the edge. Here we analyze the influence of disorder and noise on properties of the edge states and quantum-gate fidelity. We find that realistically weak disorder does not prevent one from implementation of a high-fidelity operation via the edge.
Self correction requires Energy Barrier for Abelian quantum doubles
Creators: name: Komar, Anna
name: Landon-Cardinal, Olivier
name: Temme, Kristan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We rigorously establish an Arrhenius law for the mixing time of quantum doubles based on any Abelian group $\mathbb{Z}_d$. We have made the concept of the energy barrier therein mathematically well-defined, it is related to the minimum energy cost the environment has to provide to the system in order to produce a generalized Pauli error, maximized for any generalized Pauli errors, not only logical operators. We evaluate this generalized energy barrier in Abelian quantum double models and find it to be a constant independent of system size. Thus, we rule out the possibility of entropic protection for this broad group of models.
description: 18 pages, 6 figures
Resolving Entropy Growth from Iterative Methods
Creators: name: Linders, Viktor
name: Ranocha, Hendrik
name: Birken, Philipp
Publisher: name: arXiv
Year: 2023
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65M12, 65N22, 65H10, 65F10

description: We consider entropy conservative and dissipative discretizations of nonlinear conservation laws with implicit time discretizations and investigate the influence of iterative methods used to solve the arising nonlinear equations. We show that Newton's method can turn an entropy dissipative scheme into an anti-dissipative one, even when the iteration error is smaller than the time integration error. We explore several remedies, of which the most performant is a relaxation technique, originally designed to fix entropy errors in time integration methods. Thus, relaxation works well in consort with iterative solvers, provided that the iteration errors are on the order of the time integration method. To corroborate our findings, we consider Burgers' equation and nonlinear dispersive wave equations. We find that entropy conservation results in more accurate numerical solutions than non-conservative schemes, even when the tolerance is an order of magnitude larger.
description: 25 pages, 6 figures
[C.3.15.a.] Sociétés capitalistes
Creators: name: Delmas, Georges (Dit Georges Isabelli)
Publisher: name: École des Hautes Études en Sciences Sociales; La Voix des Nôtres
Year: 2023
Subjects: http://www.idref.fr/027299031/id
http://www.idref.fr/034703926/id
http://www.idref.fr/027261468/id
http://www.idref.fr/027285332/id
http://www.idref.fr/027248925/id

Abstract
Transitions between quasi-stationary states in traffic systems: Cologne orbital motorways as an example
Creators: name: Wang, Shanshan
name: Schreckenberg, Michael
name: Guhr, Thomas
Publisher: name: arXiv
Year: 2023
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Applications (stat.AP)
subject: Machine Learning (stat.ML)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Traffic systems can operate in different modes. In a previous work, we identified these modes as different quasi-stationary states in the correlation structure. Here, we analyze the transitions between such quasi-stationary states, i.e., how the system changes its operational mode. In the longer run this might be helpful to forecast the time evolution of correlation patterns in traffic. We take Cologne orbital motorways as an example, we construct a state transition network for each quarter of 2015 and find a seasonal dependence for those quasi-stationary states in the traffic system. Using the PageRank algorithm, we identify and explore the dominant states which occur frequently within a moving time window of 60 days in 2015. To the best of our knowledge, this is the first study of this type for traffic systems.
title: The floodgates of anarchy: Some highlights from the anarchist press
Creators: name: Alexander, Don
Publisher: name: Border/lines
Year: 1990
Subjects: subject: Press, Anarchist
subject: Journalism, Anarchist

description: This article was originally published as: Alexander, D. (1990). The floodgates of anarchy: Some highlights from the anarchist press. Border/lines, 17, 2-3.
description: A vibrant, militant, political movement was built in North America in the deceptively complacent and conservative political climate of the 1980s. In the publishing world too, there is evidence of increasing anarchist activity.
Unusual ferromagnetism in Ising and Potts model on semi-directed Barabási-Albert networks
Creators: name: Sumour, Muneer A.
name: Lima, F. W. S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We check the existence of a spontaneous magnetisation of Ising and Potts spins on semi-directed Barabasi-Albert networks by Monte Carlo simulations. We verified that the magnetisation for different temperatures $T$ decays after a characteristic time $τ(T)$, which we extrapolate to diverge at positive temperatures $T_c(N)$ by a Vogel-Fulcher law, with $T_c(N)$ increasing logarithmically with network size $N$.
description: 14 pages, 8 figures
User acceptance of new EPC summary pages
Creators: name: Muhr, Laura
name: Wollenweber, Victor
name: Clanzett, Sven
name: Küttner, Sophia
Publisher: name: Zenodo
Year: 2023
Subjects: Energy Performance Certificates (EPCs)
current EPC schemes
new EPC summary pages
acceptance comparison
t-test
suggested improvements

description: This report documents two tasks carried out in the ePANACEA project: the developing process of the new EPC summary pages and the final acceptance test – testing and comparing the acceptance regarding current EPC schemes of the ePANACEA pilot countries (Spain, Belgium (Flemish region), Finland, Austria and Greece) and the new EPC summary pages. The new EPC summary pages are the result of the integration of reflected feedback received from previous user interviews, workshops, REB meetings and project partners. Therefore, the version of this project first of all includes the information that the market demands, following what the ePANACEA methodology can deliver and what the revision of the EPBD envisages. Within the ePanacea project, a series of accompanying acceptance research methods were conducted including interviews, standardized questionnaires and user workshops. For the final acceptance test, a third round of online user workshops with end-users and other stakeholders of EPC was conducted in the ePANACEA pilot countries (Spain, Belgium (Flemish region), Finland, Austria and Greece). The acceptance of the participants was mainly surveyed through online questionnaires, which were filled out during and after the workshop. To compare the acceptance regarding the EPC versions, workshop participants were divided into two groups, while one group received the current and the other group the new EPC. The acceptance of EPC versions was tested based on e.g. the understanding of information, the perceived ease of use and usefulness of the EPC, feelings regarding the presented EPC, attitude towards the presented EPC and the use intention. A t-test was calculated in order to find out whether the differences in answers between EPC groups was significant. In total 159 participants took part in the third round of workshops, meeting the target number of 30 participants per workshop in four of five pilot countries.
Embedding semiclassical periodic orbits into chaotic many-body Hamiltonians
Creators: name: Hallam, Andrew
name: Desaules, Jean-Yves
name: Papić, Zlatko
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Protecting coherent quantum dynamics from chaotic environment is key to realizations of fragile many-body phenomena and their applications in quantum technology. We present a general construction that embeds a desired periodic orbit into a family of non-integrable many-body Hamiltonians, whose dynamics is otherwise chaotic. Our construction is based on time dependent variational principle that projects quantum dynamics onto a manifold of low-entangled states, and it complements earlier approaches for embedding non-thermal eigenstates, known as quantum many-body scars, into thermalizing spectra. By designing terms that suppress "leakage" of the dynamics outside the variational manifold, we engineer families of Floquet models that host exact scarred dynamics, as we illustrate using a driven Affleck-Kennedy-Lieb-Tasaki model and a recent experimental realization of scars in a dimerized superconducting qubit chain.
description: 6+13 pages
Perspectives on adaptive dynamical systems
Creators: name: Sawicki, Jakub
name: Berner, Rico
name: Loos, Sarah A. M.
name: Anvari, Mehrnaz
name: Bader, Rolf
name: Barfuss, Wolfram
name: Botta, Nicola
name: Brede, Nuria
name: Franović, Igor
name: Gauthier, Daniel J.
name: Goldt, Sebastian
name: Hajizadeh, Aida
name: Hövel, Philipp
name: Karin, Omer
name: Lorenz-Spreen, Philipp
name: Miehl, Christoph
name: Mölter, Jan
name: Olmi, Simona
name: Schöll, Eckehard
name: Seif, Alireza
name: Tass, Peter A.
name: Volpe, Giovanni
name: Yanchuk, Serhiy
name: Kurths, Jürgen
Publisher: name: arXiv
Year: 2023
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: FOS: Physical sciences

description: Adaptivity is a dynamical feature that is omnipresent in nature, socio-economics, and technology. For example, adaptive couplings appear in various real-world systems like the power grid, social, and neural networks, and they form the backbone of closed-loop control strategies and machine learning algorithms. In this article, we provide an interdisciplinary perspective on adaptive systems. We reflect on the notion and terminology of adaptivity in different disciplines and discuss which role adaptivity plays for various fields. We highlight common open challenges, and give perspectives on future research directions, looking to inspire interdisciplinary approaches.
description: 46 pages, 9 figures
Эффекты запаздывания в спектре экранированных двумерных плазмонов
Creators: name: Андреев, И.В.
name: Семенов, Н.Д.
name: Муравьев, В.М.
Publisher: name: Институт физики твердого тела РАН
Year: 2020

description: Эффекты запаздывания в спектре экранированных двумерных плазмонов И.В.Андреев, Н.Д.Семенов, В.М.Муравьев ИФТТ РАН, 142432, г. Черноголовка Московской обл., ул. Академика Осипьяна, д.2 e-mail: andreevissp.ac.ru Исследования взаимодействия света с возбуждениями в среде представляет собой обширную и важную область задач современной физики конденсированного состояния. Одним из примеров такого взаимодействия являются эффекты запаздывания для плазменных волн в двумерных электронных системах (ДЭС), приводящие к гибридизации плазмонов со светом и возникновению гибридных квазичастиц плазмон-поляритонов. Влияние эффектов запаздывания на спектр обычных двумерных плазмонов хорошо изучено 1, 2. Представляет интерес экспериментальное исследование проявлений эффектов запаздывания также и в спектре сильно экранированных двумерных плазмонов, чего до настоящего времени не было сделано. Современная теория 3 предсказывает, что для экранированных двумерных плазмонов в магнитном поле систематический учёт эффектов запаздывания приводит к перенормировке плазменной и циклотронной частот, причём эффекты гибридизации плазмонов со светом в экранированном случае оказываются сильнее, чем в неэкранированном. В данной работе мы экспериментально исследовали микроволновый отклик дисков ДЭС, оснащенных металлическим задним затвором. Была исследована магнитодисперсия экранированного магнитоплазмона в диске, в условиях, когда одновременно реализуются режим сильного экранирования и режим сильного запаздывания. Экспериментально установлено, что в режиме сильного запаздывания за счет релятивистских эффектов происходит перенормировка как плазменной, так и циклотронной частот, приводящая к их уменьшению в несколько раз, при этом уравнение для магнитодисперсии плазменных волн в диске сохраняет свой вид для перенормированных частот. Показано, что степенью проявления эффектов запаздывания, т. е. силой плазмон-фотонного взаимодействия можно управлять, изменяя электронную плотность в ДЭС либо расстояние между ДЭС и затвором. Работа выполнена в рамках государственного задания ИФТТ РАН при частичной финансовой поддержке РФФИ (проект 18-02-00753). Литература 1 I.V. Kukushkin, J.H. Smet, S.A. Mikhailov, D.V. Kulakovskii, K. von Klitzing, and W. Wegscheider, Phys. Rev. Lett. 90, 156801 (2003). 2 P.A. Gusikhin, V.M. Muravev, A.A. Zagitova, and I.V. Kukushkin, Phys. Rev. Lett. 121, 176804 (2018). 3 A.A. Zabolotnykh and V.A. Volkov, to be published.
Время релаксации циклотронного резонанса в двумерной электронной системе
Creators: name: Андреев, И.В.
name: Семенов, Н.Д.
name: Муравьев, В.М.
Publisher: name: Институт физики твердого тела РАН
Year: 2020

description: Время релаксации циклотронного резонанса в двумерной электронной системе И.В.Андреев, Н.Д.Семенов, В.М.Муравьев ИФТТ РАН, 142432, Черноголовка, Московская обл., ул. Академика Осипьяна, д.2 e-mail: andreevissp.ac.ru В данной работе проведено экспериментальное сравнение циклотронного и транспортного времени столкновительной релаксации в двумерных электронных системах (ДЭС). Под циклотронным временем релаксации понимается время, определяющее ширину линии объемной магнитоплазменной моды в переделе сильных магнитных полей, когда она асимптотически стремится к одночастичному циклотронному резонансу. В работе удалось реализовать режим, в котором излучательный вклад в ширину линии циклотронного резонанса пренебрежимо мал. Обычно (см. напр. 1) принято считать, что из-за неэффективности малоуглового рассеяния транспортное время релаксации больше циклотронного. В данной работе, в частности, показано, что это утверждение необязательно верно. В эксперименте была исследована зависимость циклотронного и транспортного времени релаксации от температуры в диапазоне 1.5-100 К для образца с электронной плотностью 2.41011 см-2. Показано, что с ростом температуры уменьшается как циклотронное, так и транспортное время релаксации, причем циклотронное время стремится к транспортному. Это можно объяснить влиянием различных механизмов релаксации: при низких температурах доминирует рассеяние на дальнодействующем потенциале доноров, а при высоких электрон-фононное рассеяние. Также была исследована зависимость времени релаксации циклотронного резонанса от электронной плотности ДЭС в диапазоне значений 2109-31011 см-2 (Рис. 1). Экспериментально показано, что в области малых концентраций (менее 41010 см-2) циклотронное время релаксации может в несколько раз превосходить транспортное. Этот результат показывает, что в условиях низких электронных концентраций и сильной локализации в ДЭС существуют группы носителей заряда с существенно отличающимися временами релаксации. При этом измеренные в эксперименте циклотронные и транспортные времена соответствуют величинам, усредненным по разным группам носителей заряда. Работа выполнена в рамках государственного задания ИФТТ РАН. Литература 1 R. Masutomi, K. Sasaki, I. Yasuda, A. Sekine, K. Sawano, Y. Shiraki, and T. Okamoto, Phys. Rev. Lett. 106, 196404 (2011).
Phase solitons and domain dynamics in an optically injected semiconductor laser
Creators: name: Gustave, F.
name: Columbo, L.
name: Tissoni, G.
name: Brambilla, M.
name: Prati, F.
name: Barland, S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We analyze experimentally and theoretically the spatio-temporal dynamics of a highly multimode semiconductor laser with coherent optical injection. Due to the particular geometry of the device (a 1~m long ring cavity), the multimode dynamics can be resolved in real time and we observe stable chiral solitons and domain dynamics. The experiment is analyzed in the framework of a set of effective semiconductor Maxwell-Bloch equations. We analyze the stability of stationary solutions and simulate both the complete model and a reduced rate equation model. This allows us to predict domain shrinking and the stability of only one chiral charge that we ascribe to the finite active medium response time.
description: 10 pages, 12 figures
Межподзонный плазмон как детектор спиновой поляризации в двумерной электронной системе на основе MgZnO / ZnO
Creators: name: Ваньков, А.Б.
Publisher: name: Институт физики твердого тела РАН
Year: 2020

description: Межподзонный плазмон как детектор спиновой поляризации в двумерной электронной системе на основе MgZnO / ZnO А.Б.Ваньков ИФТТ РАН, 142432, Черноголовка, Московская обл., ул. Академика Осипьяна, д.2 e-mail: vankovissp.ac.ru Методом неупругого рассеяния света исследована магнитополевая динамика межподзонных коллективных возбуждений в двумерных электронных системах (ДЭС) на основе гетероструктур MgxZn1x O / ZnO. Обнаружено, что при изменении спиновой поляризации в условиях перехода от парамагнитного состояния (с фактором заполнения n 2) к холловскому ферромагнетику (n 1) энергия межподзонного магнитоплазмона значительно изменяется (Рис.1, красные символы). Это эффект согласуется с данными по альтернативному зондированию спиновой поляризации 1. Проведенный теоретический анализ показал связь данного эффекта с сопутствующим изменением обменного взаимодействия в энергии возбуждения. Ввиду этого энергия межподзонного плазмона может выступать в качестве детектора спиновой поляризации основного состояния ДЭС 2. Работа выполнена в рамках государственного задания ИФТТ РАН за счет гранта РНФ 19-72-30003. Литература 1 A. B. Vankov, B. D. Kaysin, and I. V. Kukushkin, Phys.Rev.B 96, 235401 (2017). 2 Л.В. Кулик, А.Б. Ваньков, Б.Д. Кайсин, И.В. Кукушкин, Письма в ЖЭТФ, том 105, вып. 6, с. 358-362 (2017).
Быстрый спиновый транспорт в холловском диэлектрике
Creators: name: Горбунов, А.В.
name: Журавлев, А.С.
name: Кулик, Л.В.
name: Тимофеев, В.Б.
Publisher: name: Институт физики твердого тела РАН
Year: 2020

description: Быстрый спиновый транспорт в холловском диэлектрике А.В.Горбунов, А.С.Журавлев, Л.В.Кулик, В.Б.Тимофеев ИФТТ РАН, 142432, Черноголовка, Московская обл., ул. Академика Осипьяна, д.2 e-mail: gorbunovissp.ac.ru В квантово-холловском диэлектрике (фактор заполнения 2) нижайшее по энергии возбуждение это триплетный циклотронный магнитоэкситон (ТЦМЭ), состоящий из электрона на пустом первом уровне Ландау и электронной вакансии (Ферми-дырки) на полностью занятом нулевом уровне Ландау. ТЦМЭ представляет собой оптически не активный композитный бозон со спином S 1, время жизни которого может достигать 1 мс 1. За счет столь большого времени жизни удается создать ансамбль ТЦМЭ с плотностью nex 1010 см-2 с помощью довольно слабого фотовозбуждения, что при температурах T 1 K приводит к формированию нового состояния магнетофермионного конденсата (МФК), способного быстро растекаться на макроскопические расстояния 1, 2. Прямое измерение скорости переноса спина с помощью визуализации растекания МФК здесь невозможно: попытка сформировать конденсат в малом пятне с помощью одного короткого импульса накачки неизбежно приведет к перегреву электронной системы. Оценить скорость переноса спина vprop удалось в экспериментах с импульсно-периодическим фотовозбуждением в широком пятне накачки диаметром dp 1.5 мм. Зондирование проводилось с помощью фотоиндуцированного резонансного отражения (ФРО) излучения непрерывного лазера, настроенного в резонанс с переходом электрона с уровня тяжелой дырки валентной зоны на уровень Ферми-дырки в зоне проводимости. Период следования импульсов накачки, Tp 10 мс, превышал времена всех переходных процессов в системе. При фиксированной пиковой мощности накачки Pp и постепенном наращивании длительности импульса p реализуются три режима (см. Рис. 1). В разреженном газе ТЦМЭ (область I) заполнены состояния вблизи нулевых квазиимпульсов, q 0, экситоны не успевают уходить из пятна накачки, а время спада сигнала ФРО по окончании импульса накачки d это время их энергетической релаксации. В режиме II за счет экситон-экситонного рассеяния начинают заполняться состояния вблизи минимума дисперсионной зависимости ТЦМЭ, q 1/lB 106 см-1, откуда релаксация затруднена из-за невозможности отдать столь большой импульс, поэтому d возрастает. Наконец, при высокой плотности ТЦМЭ (область III) образуется МФК, и время d связано со скоростью разбегания экситонов из пятна накачки: d dp/2vprop. Минимальное измеренное время спада 30 мкс дает оценку для скорости 25 м/с. Столь высокие скорости переноса спина делают квантово-холловский изолятор перспективным объектом для быстрой передачи сигналов в спиновой подсистеме. Литература 1 L.V. Kulik, A. S. Zhuravlev, S. Dickmann, A.V. Gorbunov, V.B. Timofeev, I.V. Kukushkin, and S. Schmult, Nature Comm. 7, 13499 (2016). 2 L.V. Kulik, V.A. Kuznetsov, A. S. Zhuravlev, A.V. Gorbunov, V.V. Solovyev, V.B. Timofeev, I.V. Kukushkin, and S. Schmult, Scientific Rep. 8, 10948 (2018).
On the sizes of ionized bubbles around the highest redshift galaxies. Spectral shapes of the Lyman-alpha emission from galaxies
Creators: name: Hayes, Matthew J.
name: Scarlata, Claudia
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We develop a new method to determine the distance between a high-redshift galaxy and a foreground screen of atomic hydrogen. In a partially neutral universe, and assuming spherical symmetry, this equates to the radius of a ionized 'bubble' (R_B) surrounding the galaxy. The method requires an observed Lya equivalent width, its velocity offset from systemic, and an input Lya profile for which we adopt scaled versions of the profiles observed in low-z galaxies. We demonstrate the technique in a sample of 23 galaxies at z > 6, including eight at z = 7.2 - 10.6 recently observed with JWST. Our model estimates the emergent Lya properties, and the foreground distance to the absorbing IGM. We find that galaxies at z > 7.5 occupy smaller bubbles (~0.5 - 1 pMpc) than those at lower-z. With a relationship that is secure at 99% confidence, we empirically demonstrate the growth of ionized regions during the reionization epoch for the first time. We independently estimate the upper limit on the Strömgren radii (R_S), and derive the escape fraction of ionizing photons budget necessary for reionization.
description: 8 pages, 7 figures. Submitted to ApJL after addressing referee comments
Спектр двумерных «прокси» плазмонов
Creators: name: Гусихин, П.А.
name: Зарезин, А.М.
name: Дремин, А.А.
name: Муравьев, В.М.
Publisher: name: Институт физики твердого тела РАН
Year: 2020

description: Спектр двумерных прокси плазмонов П.А.Гусихин, 1 А.М.Зарезин, 1,2 А.А.Дремин, 1 В.М.Муравьев1 1ИФТТ РАН, 142432, Московская обл., г. Черноголовка, ул. Академика Осипьяна, д.2 2МФТИ (НИУ), 141701, Московская обл., г. Долгопрудный, Институтский пер., д.9 e-mail: gusikhinissp.ac.ru Недавно было обнаружено, что в двумерной электронной системе (ДЭС), частично экранированной металлическим затвором, возникает совершенно новое семейство плазменных возбуждений, которые отличаются как от обычных двумерных плазмонов, так и от экранированных плазмонов 1,2. Теоретически было показано, что в случае, если затвор имеет форму длинной полоски, шириной W, то закон дисперсии новых прокси плазмонов (proximity plasmons) описывается формулой: ((q)((2n_s e2 h)/(m _0 ) q/W) AND (qW1), AND (1) ) где ns концентрация электронов в ДЭС, h расстояние от ДЭС до затвора, m эффективная масса электронов в ДЭС. В данной работе путём подбора геометрических параметров образца, схематическое изображение которого, приведено на Рис. 1, удалось возбудить серию стоячих плазмонных мод, что позволило надёжно экспериментально подтвердить теоретическое предсказание (1). Образцы были изготовлены из высококачественных гетероструктур GaAs/AlxGa1-xAs, содержащих одиночную квантовую яму. Концентрация электронов в ДЭС составляла ns 2.41011 см-2, а подвижность 4106 см2/(Вс). Для проведения экспериментов использовалась оптическая методика детектирования микроволнового поглощения в ДЭС. В результате были получены магнитополевые зависимости частоты резонансов (Рис. 1), хорошо описываемые теоретической зависимостью: 2 (B)2 (0)_c2,(2) где c циклотронная частота, за исключением того факта, что из-за эффектов запаздывания наклон зависимости меняется. В нулевом магнитном поле значения частот нескольких последовательных мод отлично описываются формулой (1), если подставить значения волнового вектора q N/L, где L длина полоски. Работа выполнена в рамках госзадания ИФТТ РАН. Литература 1 A.A. Zabolotnykh and V.A. Volkov, Phys. Rev. B 99, 165304 (2019). 2 V.M. Muravev, P.A. Gusikhin, A.M. Zarezin, I.V. Andreev, S.I. Gubarev, and I.V. Kukushkin, Phys. Rev. B 99, 241406(R) (2019).
Orbit-spin coupling and the interannual variability of global-scale dust storm occurrence on Mars
Creators: name: Shirley, James H.
name: Mischna, Michael A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: A new physical hypothesis predicts that a weak coupling of the orbital and rotational motions of extended bodies may give rise to a modulation of circulatory flows within their atmospheres. Driven cycles of intensification and relaxation of large-scale circulatory flows are predicted, with the phasing of these changes linked directly to the rate of change of the orbital angular momentum with respect to inertial frames. We test the hypothesis that global-scale dust storms (GDS) on Mars may occur when periods of circulatory intensification (associated with positive and negative extrema of the waveform) coincide with the southern summer dust storm season on Mars. The orbit-spin coupling hypothesis additionally predicts that the intervening transitional periods, which are characterized by the disappearance and subsequent sign change of this waveform, may be unfavorable for the occurrence of GDS, when they occur during the southern summer dust storm season. These hypotheses are confirmed through comparisons between calculated dynamical time series of the time rate of change of orbital angular momentum and historic observations. All of the nine known global-scale dust storms on Mars took place during Mars years when circulatory intensification during the dust storm season is predicted under the orbit-spin coupling hypothesis. No historic global-scale dust storms were recorded during transitional intervals. Orbit-spin coupling accelerations evidently contribute to the interannual variability of the Mars atmosphere.
description: 44 pages, 7 figures
Wrapping corrections for non-diagonal boundaries in AdS/CFT
Creators: name: Bajnok, Zoltan
name: Nepomechie, Rafael I.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider an open string stretched between a Y=0 brane and a Y_theta=0 brane. The latter brane is rotated with respect to the former by an angle theta, and is described by a non-diagonal boundary S-matrix. This system interpolates smoothly between the Y-Y (theta =0) and the Y-bar Y (theta = pi/2) systems, which are described by diagonal boundary S-matrices. We use integrability to compute the energies of one-particle states at weak coupling up to leading wrapping order (4, 6 loops) as a function of the angle. The results for the diagonal cases exactly match with those obtained previously.
description: 21 pages, 1 figure
[C.3.18.a.] Pobre Desterrado
Creators: name: Delmas, Georges (Dit Georges Isabelli)
Publisher: name: École des Hautes Études en Sciences Sociales; La Voix des Nôtres
Year: 2023
Subjects: http://www.idref.fr/028135350/id
http://www.idref.fr/034703926/id
http://www.idref.fr/027456625/id
http://www.idref.fr/027261468/id

Abstract