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Related papers: Markovian Matrix Product Density Operators : Effic…

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Dynamics of non-Markovian systems is a classic problem yet it attracts an everlasting activity in physics and beyond. A powerful tool for modeling such setups is the Generalized Langevin Equation, however, its analysis typically poses a…

Statistical Mechanics · Physics 2024-10-29 Mateusz Wiśniewski , Jakub Spiechowicz

We present a systematic perturbative construction of the most general metric operator (and positive-definite inner product) for quasi-Hermitian Hamiltonians of the standard form, H= p^2/2 + v(x), in one dimension. We show that this problem…

Quantum Physics · Physics 2009-11-11 Ali Mostafazadeh

We consider the generic model of a finite-size quantum electron system connected to two (temperature and particle) reservoirs. The quantum open system is driven out of equilibrium by the presence of both a temperature and a chemical…

Statistical Mechanics · Physics 2017-04-04 H. Ness

We investigate and ascertain the ideal inputs to any finite-time thermodynamic process. We demonstrate that the expectation values of entropy flow, heat, and work can all be determined via Hermitian observables of the initial state. These…

Quantum Physics · Physics 2023-05-02 Paul M. Riechers , Chaitanya Gupta , Artemy Kolchinsky , Mile Gu

Entropy production and the detailed fluctuation theorem are of fundamental importance for thermodynamic processes. In this paper, we study the multiple entropy production for multitime quantum processes in a unified framework. For closed…

Quantum Physics · Physics 2023-09-27 Zhiqiang Huang

Evolution of charged quantum fields under the action of constant nonuniform electric fields is studied. To this end we construct a special generating functional for density operators of the quantum fields with different initial conditions.…

High Energy Physics - Theory · Physics 2019-06-25 S. P. Gavrilov , D. M. Gitman , A. A. Shishmarev

We present a partition-free approach to the evolution of density matrices for open quantum systems coupled to a harmonic environment. The influence functional formalism combined with a two-time Hubbard-Stratonovich transformation allows us…

Quantum Physics · Physics 2017-03-29 G. M. G. McCaul , C. D. Lorenz , L. Kantorovich

We present a technique to compute the microcanonical thermodynamical properties of a manybody quantum system using tensor networks. The Density Of States (DOS), and more general spectral properties, are evaluated by means of a…

Quantum Physics · Physics 2017-09-07 Fabian Schrodi , Pietro Silvi , Ferdinand Tschirsich , Rosario Fazio , Simone Montangero

A link between memory effects in quantum kinetic equations and nonequilibrium correlations associated with the energy conservation is investigated. In order that the energy be conserved by an approximate collision integral, the one-particle…

Statistical Mechanics · Physics 2007-05-23 V. G. Morozov , Gerd Ropke

We review the properties of reduced density matrices for free fermionic or bosonic many-particle systems in their ground state. Their basic feature is that they have a thermal form and thus lead to a quasi-thermodynamic problem with a…

Statistical Mechanics · Physics 2015-05-13 Ingo Peschel , Viktor Eisler

The focus is on understanding the quantum thermodynamics of strongly coupled non-Markovian quantum systems. To this end, a non-trivial, non-Markovian model of a central spin surrounded by a spin bath is taken up, and its exact evolution is…

Quantum Physics · Physics 2025-08-28 Devvrat Tiwari , Baibhab Bose , Subhashish Banerjee

A central concept in the connection between physics and information theory is entropy, which represents the amount of information extracted from the system by the observer performing measurements in an experiment. Indeed, Jaynes' principle…

Quantum Physics · Physics 2018-11-13 Matheus Capela , Mikel Sanz , Enrique Solano , Lucas C. Céleri

We propose a series of quantum algorithms for computing a wide range of quantum entropies and distances, including the von Neumann entropy, quantum R\'{e}nyi entropy, trace distance, and fidelity. The proposed algorithms significantly…

Quantum Physics · Physics 2024-07-29 Qisheng Wang , Ji Guan , Junyi Liu , Zhicheng Zhang , Mingsheng Ying

Contrary to conventional quantum mechanics, which treats measurement as instantaneous, here we explore a model for finite-time measurement. The main two-level system interacts with the measurement apparatus in a Markovian way described by…

Just as matrix product states represent ground states of one-dimensional quantum spin systems faithfully, continuous matrix product states (cMPS) provide faithful representations of the vacuum of interacting field theories in one spatial…

Quantum Physics · Physics 2022-01-20 Benoît Tuybens , Jacopo De Nardis , Jutho Haegeman , Frank Verstraete

We provide a rigorous construction of Markovian master equations for a wide class of quantum systems that encompass quadratic models of finite size, linearly coupled to an environment modeled by a set of independent thermal baths. Our…

Quantum Physics · Physics 2021-05-18 Antonio D'Abbruzzo , Davide Rossini

Considering a kicked rotor coupled to a model heat bath both the classical and quantum entropy productions are calculated exactly. Starting with an initial wave packet, the von Neuman entropy as a function of time is determined from the…

Quantum Physics · Physics 2009-11-07 Sankhasubhra Nag , Avijit Lahiri , Gautam Ghosh

Simulating quantum many-body systems (QMBS) is one of the long-standing, highly non-trivial challenges in condensed matter physics and quantum information due to the exponentially growing size of the system's Hilbert space. To date, tensor…

Quantum Physics · Physics 2026-02-06 Belal Abouraya , Jirawat Saiphet , Fedor Jelezko , Ressa S. Said

Theoretical understanding of the scaling of entropies and the mutual information has led to significant advances in the research of correlated states of matter, quantum field theory, and gravity. Measuring von Neumann entropy in quantum…

Quantum simulation is a promising application of future quantum computers. Product formulas, or Trotterization, are the oldest and still remain an appealing method to simulate quantum systems. For an accurate product formula approximation,…

Quantum Physics · Physics 2024-11-04 Chi-Fang , Chen , Fernando G. S. L. Brandão