Article
Mechanics
Thorsten Bartel, Gian-Luca Geuken, Andreas Menzel
Summary: A thermodynamically consistent constitutive framework is introduced to accurately capture the time-dependent behavior of austenite-to-bainite phase transformations. Plasticity-like evolution equations are used to describe the diffusion-controlled processes, along with the adoption of a variational principle and an additional term to ensure thermodynamical consistency and specific modifications in the model. Material parameters are determined based on experimental results for 51CrV4, allowing for quantitative evaluation of predicted results.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2021)
Article
Optics
Bo Yang, Bo Xiong, Zilong Liu, Bo Zhang
Summary: This study investigates the formation of spatial correlation in a two-dimensional dissipative Rydberg system using the time-dependent variational principle. The results show that a moderately large decay rate, induced by the two-photon excitation scheme, significantly suppresses the buildup of correlation in a long-time scale. Additionally, a relatively large dephasing rate leads to a shorter relaxation time for the antiferromagnetic correlation to reach a stable value.
Review
Chemistry, Physical
Michael Werther, Sreeja Loho Choudhury, Frank Grossmann
Summary: This review comprehensively compares CS methods to solve the TDSE, including VCS, CCS, and HK methods, by testing on a 1D Morse oscillator for revival dynamics, focusing on the number of basis states needed for convergence and the issue of tight frames. Different discretisation strategies for phase space integrals and the apoptosis procedure in the VCS method are also discussed, with the Holstein molecular crystal model serving as an illustration.
INTERNATIONAL REVIEWS IN PHYSICAL CHEMISTRY
(2021)
Article
Physics, Multidisciplinary
Hadiseh Alaeian, Berislav Buca
Summary: In this study, by utilizing modulated dynamical symmetries, the existence of multistability in the presence of quantum fluctuations is exactly proven in a driven-dissipative fermionic chain. Unlike the mean-field level, the quantum fluctuations themselves exhibit multistability.
COMMUNICATIONS PHYSICS
(2022)
Article
Physics, Mathematical
Joseph Ryan
Summary: The dynamics of some non-conservative and dissipative systems can be derived using the first variation of an action-dependent action based on Herglotz's variational principle. Similar to the Hamiltonian variational principle for conservative systems, the second variation of the action-dependent action can determine the dynamic stability of possible trajectories for non-conservative and dissipative systems. This paper generalizes previous analyses and demonstrates how to calculate the second variation of the action-dependent action, applying it to both the time-independent and time-dependent harmonic oscillators.
JOURNAL OF MATHEMATICAL PHYSICS
(2023)
Article
Mathematics, Applied
Riccardo Cesari, Harry Zheng
Summary: In this paper, we study a general optimal liquidation problem with a control-dependent stopping time and prove a new stochastic maximum principle. Through a simple example, we find that the optimal solution satisfies the stochastic maximum principle in this paper but fails the standard stochastic maximum principle in previous literature.
APPLIED MATHEMATICS AND OPTIMIZATION
(2022)
Article
Materials Science, Multidisciplinary
Amit Acharya
Summary: An action functional is developed for nonlinear dislocation dynamics, aiming to use effective field theory to describe the macroscopic behavior of plasticity in crystalline solids. This work reveals connections between continuum mechanics, material science of defects in solids, effective field theory techniques in physics, and fracton tensor gauge theories.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Mathematics, Applied
Kang-Jia Wang, Guo-Dong Wang
Summary: This paper investigates the time-space fractional Drinfeld-Sokolov-Wilson system and solves its solitary solutions using He's variational method and the two-scale transform. The applicability and efficiency of the approach are demonstrated through numerical results. The main advantage of the variational approach is its ability to simplify the differential equation.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2023)
Article
Mechanics
Xiao-Jian Xu, Jun-Miao Meng
Summary: A size-dependent elastic theory for magneto-electro-elastic (MEE) nano-materials is proposed, which includes classical and nonlocal parameters. Governing equations and boundary conditions are derived with the aid of the variational principle. General solutions for a one-dimensional beam problem are formulated, with the motion equation two orders higher than the classical model.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2021)
Article
Optics
Albert Cabot, Leah Sophie Muhle, Federico Carollo, Igor Lesanovsky
Summary: In this study, we explore the boundary time-crystal transition at the quantum trajectory level through continuous monitoring. The experiments show that the photon count signal and the homodyne current can be used to identify and characterize critical behavior at the time-crystal phase transition. The oscillation patterns in the time-crystal phase can be observed in finite systems and individual realizations, while the emission signals exhibit intermittent strong fluctuations at the transition point.
Article
Physics, Multidisciplinary
Jae-Mo Lihm, Cheol-Hwan Park
Summary: The self-consistent harmonic approximation is proven useful for studying the equilibrium properties of anharmonic lattices, but the study of dynamical properties still requires further exploration. By applying the time-dependent variational principle, an analytical formula for position-position correlation function and phonon self-energy in anharmonic lattice is derived, confirming the dynamical ansatz of the self-consistent harmonic approximation. This work establishes a fruitful connection between the time-dependent variational principle and anharmonic lattice Hamiltonian, providing insights in both fields.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Materials Science, Multidisciplinary
Fengxian Liu, Alan C. F. Cocks, Edmund Tarleton
Summary: Diffusion plays a crucial role in dislocation motion, with lattice diffusion dominating at high temperatures and core diffusion dominating at low temperatures. However, there is currently no quantitative definition for the conditions under which each diffusion mechanism is dominant. This study combines variational principle and finite element analysis to consider the competition and synergy between core and lattice diffusion, and constructs a diffusion mechanism map to guide the evolution of dislocation loops.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Astronomy & Astrophysics
Dipika Dash, Samapan Bhadury, Sunil Jaiswal, Amaresh Jaiswal
Summary: In this study, a new framework for deriving relativistic dissipative hydrodynamics from the Boltzmann equation with energy-dependent relaxation time is developed. The framework is shown to be compatible with conservation laws and corrections to transport coefficients due to energy dependence of relaxation time are discussed. The ratios of these transport coefficients are studied using a parametrized relaxation-time, revealing interesting scaling features.
Article
Astronomy & Astrophysics
Dipika Dash, Samapan Bhadury, Sunil Jaiswal, Amaresh Jaiswal
Summary: Development of a new framework for deriving order-by-order hydrodynamics from the Boltzmann equation is necessary to address the violations of conservation laws caused by the widely used Anderson-Witting formalism when relaxation-time depends on particle energy or in a hydrodynamic frame other than the Landau frame. In this study, we generalize an existing framework and extend the Anderson-Witting relaxation-time approximation to derive relativistic dissipative hydrodynamics consistently. The present framework is compatible with conservation laws and yields first-order hydrodynamic equations in the Landau frame. Additionally, corrections to the transport coefficients due to energy dependence of the relaxation-time are observed, indicating deviations from the Anderson-Witting approximation.
Article
Physics, Multidisciplinary
A. G. Abanov, P. B. Wiegmann
Summary: We study the flows of barotropic perfect fluid under the simultaneous action of the electromagnetic field and the axial-vector potential. By analyzing the deformation of the Euler equation and various currents caused by the two external fields, we demonstrate that the divergence of the vector and axial currents is controlled by the chiral anomaly known in quantum field theories with Dirac fermions. These results are obtained by extending the variational principle for barotropic flows of a perfect fluid by coupling with the external axial-vector potential.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Physics, Multidisciplinary
Cedric Beny, Tobias J. Osborne
NEW JOURNAL OF PHYSICS
(2015)
Article
Physics, Multidisciplinary
Florian Richter, Daniel Becker, Cedric Beny, Torben A. Schulze, Silke Ospelkaus, Tobias J. Osborne
NEW JOURNAL OF PHYSICS
(2015)
Article
Physics, Multidisciplinary
David Jennings, Christoph Brockt, Jutho Haegeman, Tobias J. Osborne, Frank Verstraete
NEW JOURNAL OF PHYSICS
(2015)
Article
Physics, Multidisciplinary
C. Eichler, J. Mlynek, J. Butscher, P. Kurpiers, K. Hammerer, T. J. Osborne, A. Wallraff
Article
Physics, Particles & Fields
Wissam Chemissany, Tobias J. Osborn
JOURNAL OF HIGH ENERGY PHYSICS
(2016)
Article
Physics, Multidisciplinary
Leander Fiedler, Pieter Naaijkens, Tobias J. Osborne
NEW JOURNAL OF PHYSICS
(2017)
Article
Multidisciplinary Sciences
Cedric Beny, Christopher T. Chubb, Terry Farrelly, Tobias J. Osborne
NATURE COMMUNICATIONS
(2018)
Article
Optics
Kerstin Beer, Megha Khosla, Julius Koehler, Tobias J. Osborne, Tianqi Zhao
Summary: In this paper, an approach is developed to improve learning efficiency by leveraging the graph structure of the quantum source for an arbitrary quantum neural network (QNN) ansatz. A self-supervised objective is devised and optimized to capture the information-theoretic closeness of quantum states during QNN training. Numerical simulations demonstrate that this approach enhances learning efficiency and generalization behavior of the base QNN. Moreover, scalable quantum implementations of the learning procedure described in this paper are likely feasible on the next generation of quantum computing devices.
Article
Optics
Ivana Kurecic, Tobias J. Osborne
Summary: The dynamics of interacting quantum systems in the presence of disorder is studied and an exact representation for disorder-averaged quantities via Ito stochastic calculus is obtained. The stochastic integral representation allows for analytic approximation, potential applicability to interacting systems, and compatibility with tensor network methods. The integral can be expanded to produce a series of approximations, the first of which includes all diffusive corrections and is manifestly completely positive. As examples, expressions for the density of states and spectral form factor for the Anderson model are obtained.
Article
Optics
Thomas Cope, Tobias J. Osborne
Summary: This paper explores nonlocal correlations between a fully characterized quantum system and an untrusted black box device, described by conditional quantum states. The necessary and sufficient conditions for an assemblage to be extremal are given using linear independence conditions and an algorithm for decomposition. A MATLAB implementation of the algorithm is also provided.
Article
Astronomy & Astrophysics
Laura Niermann, Tobias J. Osborne
Summary: Holographic tensor networks associated with tilings of (1 + 1)-dimensional de Sitter spacetime are introduced and their basic features are discussed. A comparison is made with conjectured properties of quantum gravity in de Sitter spacetime, highlighting the correspondence between the quantum information capacity of the network and the cosmological constant.
Article
Optics
Kerstin Beer, Tobias J. Osborne
Article
Astronomy & Astrophysics
Ashley Milsted, Tobias J. Osborne
Article
Optics
A. Nikolova, G. K. Brennen, T. J. Osborne, G. J. Milburn, T. M. Stace
Article
Physics, Multidisciplinary
Jutho Haegeman, Damian Draxler, Vid Stojevic, J. Ignacio Cirac, Tobias J. Osborne, Frank Verstraete