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A dynamical many-body theory is presented which systematically extends beyond mean-field and perturbative quantum-field theoretical procedures. It allows us to study the dynamics of strongly interacting quantum-degenerate atomic gases. The…

Other Condensed Matter · Physics 2010-02-04 Thomas Gasenzer , Juergen Berges , Michael G. Schmidt , Marcos Seco

We introduce and investigate an open many-body quantum system in which kinetically constrained coherent and dissipative processes compete. The form of the incoherent dissipative dynamics is inspired by that of epidemic spreading or…

Statistical Mechanics · Physics 2022-10-12 Federico Carollo , Markus Gnann , Gabriele Perfetto , Igor Lesanovsky

We perform a detailed analysis of the non stationary solutions of the evolution (Fokker-Planck) equations associated to either stationary or non stationary quantum states by the stochastic mechanics. For the excited stationary states of…

The rapid development of quantum computers has enabled demonstrations of quantum advantages on various tasks. However, real quantum systems are always dissipative due to their inevitable interaction with the environment, and the resulting…

It has been argued that it is incompatible to maintain unitary time-evolution for time-dependent non-Hermitian Hamiltonians when the metric operator is explicitly time-dependent. We demonstrate here that the time-dependent Dyson equation…

Quantum Physics · Physics 2016-04-27 Andreas Fring , Miled H. Y. Moussa

We study the time evolution of two coupled quantum harmonic oscillators interacting through nonlinear optomechanical-like Hamiltonians that include cross-Kerr interactions. We employ techniques developed to decouple the time-evolution…

Quantum Physics · Physics 2020-03-04 David Edward Bruschi

Unitary transformations can allow one to study open quantum systems in situations for which standard, weak-coupling type approximations are not valid. We develop here an extension of the variational (polaron) transformation approach to open…

New one-leg multistep time discretizations of nonlinear evolution equations are investigated. The main features of the scheme are the preservation of the nonnegativity and the entropy-dissipation structure of the diffusive equations. The…

Numerical Analysis · Mathematics 2013-12-02 Ansgar Jüngel , Josipa-Pina Milišić

A class of non-Dirac-hermitian many-particle quantum systems admitting entirely real spectra and unitary time-evolution is presented. These quantum models are isospectral with Dirac-hermitian systems and are exactly solvable. The general…

Quantum Physics · Physics 2011-09-28 Pijush K. Ghosh

The techniques employed to solve the interaction of a detector and a quantum field typically require perturbation methods. We introduce mathematical techniques to solve the time evolution of an arbitrary number of detectors interacting with…

Quantum Physics · Physics 2014-04-01 David Edward Bruschi , Antony R. Lee , Ivette Fuentes

Extensive N-body simulations are among the key means for the study of numerous astrophysical and cosmological phenomena, so various schemes are developed for possibly higher accuracy computations. We demonstrate the principal possibility…

Instrumentation and Methods for Astrophysics · Physics 2018-11-05 V. G. Gurzadyan , V. V. Harutyunyan , A. A. Kocharyan

In the last twenty years, Rydberg atoms have become a versatile and much studied system for implementing quantum many-body systems in the framework of quantum computation and quantum simulation. However, even in the absence of coherent…

Quantum Physics · Physics 2018-10-12 O. Morsch , I. Lesanovsky

We present a model of discrete quantum evolution based on quantum correlations between the evolving system and a reference quantum clock system. A quantum circuit for the model is provided, which in the case of a constant Hamiltonian is…

Quantum Physics · Physics 2016-07-06 A. Boette , R. Rossignoli , N. Gigena , M. Cerezo

A proposal is made for a mathematically unambiguous treatment of evolution in the presence of closed timelike curves. In constrast to other proposals for handling the naively nonunitary evolution that is often present in such situations,…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Arlen Anderson

We show that the time evolution of an open quantum system, described by a possibly time dependent Liouvillian, can be simulated by a unitary quantum circuit of a size scaling polynomially in the simulation time and the size of the system.…

Quantum Physics · Physics 2011-12-23 M. Kliesch , T. Barthel , C. Gogolin , M. Kastoryano , J. Eisert

We introduce a method to efficiently study the dynamical properties of many-body localized systems in the regime of strong disorder and weak interactions. Our method reproduces qualitatively and quantitatively the real-time evolution with a…

Disordered Systems and Neural Networks · Physics 2019-07-03 Giuseppe De Tomasi , Frank Pollmann , Markus Heyl

In this work we propose an approach for implementing time-evolution of a quantum system using product formulas. The quantum algorithms we develop have provably better scaling (in terms of gate complexity and circuit depth) than a naive…

We present the time dynamics of twisted quantum states. We find an explicit connection between the well-known stationary Landau state and an evolving twisted state, even when the Hamiltonian accounts for linear energy dissipation. Utilizing…

Quantum Physics · Physics 2023-09-06 N. V. Filina , S. S. Baturin

Nonlinear differential equations model diverse phenomena but are notoriously difficult to solve. While there has been extensive previous work on efficient quantum algorithms for linear differential equations, the linearity of quantum…

In this work we combine quantum renormalization group approaches with deep artificial neural networks for the description of the real-time evolution in strongly disordered quantum matter. We find that this allows us to accurately compute…

Disordered Systems and Neural Networks · Physics 2021-07-28 Heiko Burau , Markus Heyl