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Time-dependent renormalization was employed to derive a nonlinear quantum master equation (QME), in which the dynamics of a non-equilibrium fluctuation in an irrelevant system are fed back into that of a relevant one. In terms of…

Chemical Physics · Physics 2020-01-03 Akihiro Kimura , Hanayo Tsuzuku

Loop corrections to finite-time correlation functions in quantum field theories away from equilibrium can be calculated using the in-in path integral approach. In this paper, we calculate the unequal-time two-point correlator for different…

High Energy Physics - Theory · Physics 2023-03-07 Spasen Chaykov , Nishant Agarwal , Sina Bahrami , R. Holman

Leggett-Garg's inequalities predict sharp bounds for some classical correlation functions that address the quantum or classical nature of real-time evolutions. We experimentally observe the violations of these bounds on single- and…

Quantum Physics · Physics 2022-04-06 Alessandro Santini , Vittorio Vitale

We derive the improved estimators for general interactions and employ these for the continuous-time quantum Monte Carlo method. Using a worm algorithm we show how measuring higher-ordered correlators leads to an improved high-frequency…

Strongly Correlated Electrons · Physics 2016-10-07 Patrik Gunacker , Markus Wallerberger , Tin Ribic , Andreas Hausoel , Giorgio Sangiovanni , Karsten Held

While machine learning holds great promise for quantum technologies, most current methods focus on predicting or controlling a specific quantum system. Meta-learning approaches, however, can adapt to new systems for which little data is…

A general method is introduced for verifying multitime quantum correlations through the characteristic function of the time-dependent P functional that generalizes the Glauber-Sudarshan P function. Quantum correlation criteria are derived…

Quantum Physics · Physics 2016-06-30 F. Krumm , J. Sperling , W. Vogel

In this paper we present the two-state vector formalism of quantum mechanics. It is a time-symmetrized approach to standard quantum theory particularly helpful for the analysis of experiments performed on pre- and post-selected ensembles.…

Quantum Physics · Physics 2007-06-10 Yakir Aharonov , Lev Vaidman

We propose a simple method to estimate the parameters of a continuously measured quantum system, by fitting correlation functions of the measured signal. We demonstrate the approach in simulation, both on toy examples and on a recent…

Quantum Physics · Physics 2024-10-17 Pierre Guilmin , Pierre Rouchon , Antoine Tilloy

In this work we apply deep neural networks to find the non-equilibrium steady state solution to correlated open quantum many-body systems. Motivated by the ongoing search to find more powerful representations of (mixed) quantum states, we…

Quantum Physics · Physics 2025-01-13 Johannes Mellak , Enrico Arrigoni , Wolfgang von der Linden

We extend the non-Markovian quantum state diffusion (QSD) equation to open quantum systems which exhibit multi-channel coupling to a harmonic oscillator reservoir. Open quantum systems which have multi-channel reservoir coupling are those…

Quantum Physics · Physics 2015-06-03 Curtis J. Broadbent , Jun Jing , Ting Yu , Joseph H. Eberly

In this paper we study the double scaling limit of the multi-orientable tensor model. We prove that, contrary to the case of matrix models but similarly to the case of invariant tensor models, the double scaling series are convergent. We…

High Energy Physics - Theory · Physics 2018-06-22 Razvan Gurau , Adrian Tanasa , Donald R. Youmans

A semi-Markov process method for obtaining general counting statistics for open quantum systems is extended to the scenario of resetting. The simultaneous presence of random resets and wave function collapses means that the quantum jump…

Statistical Mechanics · Physics 2023-12-15 Fei Liu

To overcome the limitations of classical partially connected Boltzmann machines and mainstream quantum Boltzmann machines (QBMs), this work extends the conventional circuit of the quantum approximate optimization algorithm (QAOA) to a…

Quantum Physics · Physics 2026-05-13 Jun Liu

Quantum systems coupled to environments exhibit intricate dynamics. The master equation gives a Markov approximation of the dynamics, allowing for analytic and numerical treatments. It is ubiquitous in theoretical and applied quantum…

Quantum Physics · Physics 2021-12-17 Marco Merkli

The wide-ranging adoption of quantum technologies requires practical, high-performance advances in our ability to maintain quantum coherence while facing the challenge of state collapse under measurement. Here we use techniques from control…

Quantum Physics · Physics 2017-02-01 Sandeep Mavadia , Virginia Frey , Jarrah Sastrawan , Stephen Dona , Michael J. Biercuk

We study an arbitrary non-equilibrium dynamics of a quantum bipartite system coupled to a reservoir. For its characterization, we present a fluctuation theorem (FT) that explicitly addresses the quantum correlation of subsystems during the…

Quantum Physics · Physics 2020-05-22 Jung Jun Park , Hyunchul Nha , Sang Wook Kim , Vlatko Vedral

What is the minimal time until a quantum system can exhibit genuine quantum features? To answer this question we derive quantum speed limits for two-time correlation functions arising from statistics of measurements. Generally, these…

Quantum Physics · Physics 2025-05-27 Sagar Silva Pratapsi , Sebastian Deffner , Stefano Gherardini

We investigate the potential of a quantum Boltzmann equation without momentum conservation for description of strongly correlated electron systems out of equilibrium. In a spirit similar to dynamical mean field theory (DMFT), the momentum…

Strongly Correlated Electrons · Physics 2018-11-07 Michael Wais , Martin Eckstein , Roland Fischer , Philipp Werner , Marco Battiato , Karsten Held

The known quantum error-correcting codes are typically built on approximative open-quantum-system models such as Born--Markov master equations. However, it is an open question how such codes perform in actual physical systems that, to some…

We develop a form factor approach to the study of dynamical correlation functions of quantum integrable models in the critical regime. As an example, we consider the quantum non-linear Schr\"odinger model. We derive long-distance/long-time…

Mathematical Physics · Physics 2017-03-17 N. Kitanine , K. K. Kozlowski , J. M. Maillet , N. A. Slavnov , V. Terras