English
Related papers

Related papers: Beyond the Quantum Regression Theorem in Variation…

200 papers

An extremely useful evolution equation that allows systematically calculating the two-time correlation functions (CF's) of system operators for non-Markovian open (dissipative) quantum systems is derived. The derivation is based on…

Quantum Physics · Physics 2011-03-30 Hsi-Sheng Goan , Po-Wen Chen , Chung-Chin Jian

Quantum information processing relies on how dynamics unfold in open quantum systems. In this work, we study the non-Markovian dynamics in the single mode spin-boson model at strong couplings. In order to apply perturbation theory, we…

Quantum Physics · Physics 2025-01-03 Rayees A Mala , Mehboob Rashid , Muzaffar Qadir Lone

With extensive variational simulations, dissipative quantum phase transitions in the sub-Ohmic spin-boson model are numerically studied in a dense limit of environmental modes. By employing a generalized trial wave function composed of…

Statistical Mechanics · Physics 2023-09-06 Yulong Shen , Nengji Zhou

Quantum resource theories (QRTs) offer a highly versatile and powerful framework for studying different phenomena in quantum physics. From quantum entanglement to quantum computation, resource theories can be used to quantify a desirable…

Quantum Physics · Physics 2019-04-23 Eric Chitambar , Gilad Gour

We propose a nonequilibrium variational polaron transformation, based on an ansatz for nonequilibrium steady state (NESS) with an effective temperature, to study quantum heat transport at the nanoscale. By combining the variational polaron…

Chemical Physics · Physics 2019-07-05 ChangYu Hsieh , Junjie Liu , Chenru Duan , Jianshu Cao

Quantum reservoir computing (QRC) is a hardware-implementation-friendly quantum neural network scheme with minimal physical system requirements and a proven advantage over classical counterparts. We use an extension of the positive-P phase…

Quantum Physics · Physics 2026-03-19 S. Świerczewski , W. Verstraelen , P. Deuar , T. C. H. Liew , A. Opala , M. Matuszewski

We investigate the validity of quantum regression for a family of quantum Hamiltonians on a multipartite system leading to phase-damping reduced dynamics. After finding necessary and sufficient conditions for the CP-divisibility of the…

Quantum Physics · Physics 2022-05-17 Davide Lonigro , Dariusz Chruściński

We analyze the problem of a quantum computer in a correlated environment protected from decoherence by QEC using a perturbative renormalization group approach. The scaling equation obtained reflects the competition between the dimension of…

Quantum Physics · Physics 2007-05-23 E. Novais , Eduardo R. Mucciolo , Harold U. Baranger

Determining the statistics of work done on a quantum system while strongly coupled to a reservoir is a formidable task, requiring the calculation of the full eigenspectrum of the combined system and reservoir. Here we show that this issue…

Quantum Physics · Physics 2026-05-28 Owen Diba , Harry J. D. Miller , Jake Iles-Smith , Ahsan Nazir

A classical fluid splitter produces the same patterns of energy redistribution as a Stern-Gerlach quantum device, with rotationally invariant coefficients of correlation between molecular paths. Alternative settings express a cosine squared…

General Physics · Physics 2026-04-23 Ghenadie N. Mardari

We consider multiple non-interacting quantum mechanical two-level systems coupled to a common bosonic bath and study its quantum phase transition with Monte Carlo simulations using a continuous imaginary time cluster algorithm. The common…

Statistical Mechanics · Physics 2014-12-10 André Winter , Heiko Rieger

Enhancing the quantum correlations in realistic quantum systems interacting with the environment of finite temperature is an important subject in quantum information processing. In this paper, we use weak measurement and measurement…

Quantum Physics · Physics 2014-06-25 Nasibollah Doustimotlagh , Shuhao Wang , Chenglong You , Gui-Lu Long

Study of dissipative quantum phase transitions in the Ohmic spin-boson model is numerically challenging in a dense limit of environmental modes. In this work, large-scale numerical simulations are carried out based on the variational…

Quantum Physics · Physics 2021-06-16 Xiaohui Qian , Congzhi Zeng , Nengji Zhou

We investigate the intricate dynamics of quantum coherence and non-classical correlations in a two-qubit open quantum system coupled to a squeezed thermal reservoir. By exploring the correlations between spatially separated qubits, we…

Quantum Physics · Physics 2026-02-24 Neha Pathania , Ramniwas Meena , Subhashish Banerjee

The generalized quantum master equation provides a powerful framework for non-Markovian dynamics of open quantum systems. However, the accurate and efficient evaluation of the memory kernel remains a challenge. In this work, we introduce a…

Chemical Physics · Physics 2026-05-26 Rui-Hao Bi , Wei Liu , Wenjie Dou

The quantum regression theorem states that the correlations of a system at two different times are governed by the same equations of motion as the temporal response of the average values. Such a relation provides a powerful framework for…

Quantum computation is one of the most promising new paradigms for the simulation of physical systems composed of electrons and atomic nuclei, with applications in chemistry, solid-state physics, materials science, and molecular biology.…

Quantum Physics · Physics 2024-11-05 Jakob Günther , Alberto Baiardi , Markus Reiher , Matthias Christandl

We study a quantum impurity possessing both translational and internal rotational degrees of freedom interacting with a bosonic bath. Such a system corresponds to a `rotating polaron', which can be used to model, e.g., a rotating molecule…

Quantile regression (QR) is a powerful tool for estimating one or more conditional quantiles of a target variable $\mathrm{Y}$ given explanatory features $\boldsymbol{\mathrm{X}}$. A limitation of QR is that it is only defined for scalar…

Computation · Statistics 2023-06-05 Aviv A. Rosenberg , Sanketh Vedula , Yaniv Romano , Alex M. Bronstein

We present the results of a study of the two-time correlation functions of a dichotomously driven two-level system in contact with a thermal bath by using corrections beyond the quantum regression theorem. In the strong system-environment…

Quantum Physics · Physics 2021-09-03 Arzu Kurt