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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

Quantum Mechanical ground states of many-body systems can be important resources for various investigations: for quantum sensing, as the initial state for nonequilibrium quantum dynamics following quenches, and the simulation of quantum…

Quantum Physics · Physics 2025-11-18 Prashasti Tiwari , Dylan Lewis , Sougato Bose

The many-body Green's function theory with the random-phase approximation is applied to the study of easy-plane spin-1/2 ferromagnets in an in-plane magnetic field. We demonstrate that the usual procedure, in which only the three Green's…

Strongly Correlated Electrons · Physics 2009-11-13 Daisuke Yamamoto , Synge Todo , Susumu Kurihara

We time-evolve a translationally invariant quantum state on the Quantinuum H1-1 trapped-ion quantum processor, studying the dynamical quantum phase transition of the transverse field Ising model. This physics requires a delicate…

We derive a closed equation of motion for the current density of an inhomogeneous quantum many-body system under the assumption that the time-dependent wave function can be described as a geometric deformation of the ground-state wave…

Other Condensed Matter · Physics 2015-05-14 Xianlong Gao , Jianmin Tao , G. Vignale , I. V. Tokatly

Nonequilibrium Green's function methods allow for an intrinsically consistent description of the evolution of quantal many-body body systems, with inclusion of different types of correlations. In this paper, we focus on the practical…

Nuclear Theory · Physics 2011-04-20 Arnau Rios , Brent Barker , Mark Buchler , Pawel Danielewicz

We propose and apply the finite-element discrete variable representation to express the nonequilibrium Green's function for strongly inhomogeneous quantum systems. This method is highly favorable against a general basis approach with regard…

Strongly Correlated Electrons · Physics 2013-05-29 K. Balzer , S. Bauch , M. Bonitz

Evolution in imaginary time is a prominent technique for finding the ground state of quantum many-body systems, and the heart of a number of numerical methods that have been used with great success in quantum chemistry, condensed matter and…

A single-time quantum transport equation, which includes effects beyond the quasiparticle approximation, is derived for Fermi-systems in the framework of non-equilibrium real-time Green's functions theory. Ternary correlations are…

Nuclear Theory · Physics 2009-10-30 A. Sedrakian , G. Roepke

In this paper, the ground state Wigner function of a many-body system is explored theoretically and numerically. First, an eigenvalue problem for Wigner function is derived based on the energy operator of the system. The validity of finding…

Quantum Physics · Physics 2021-11-24 Hongfei Zhan , Zhenning Cai , Guanghui Hu

We consider quantum spin chains with a hidden free fermionic structure, distinct from the Jordan-Wigner transformation and its generalizations. We express selected local operators with the hidden fermions. This way we can exactly solve the…

Statistical Mechanics · Physics 2025-04-14 István Vona , Márton Mestyán , Balázs Pozsgay

Efficient representation of quantum many-body states on classical computers is a problem of enormous practical interest. An ideal representation of a quantum state combines a succinct characterization informed by the system's structure and…

Quantum Physics · Physics 2023-04-11 Abhijith Jayakumar , Marc Vuffray , Andrey Y. Lokhov

This work presents a novel realization approach to Quantum Boltzmann Machines (QBMs). The preparation of the required Gibbs states, as well as the evaluation of the loss function's analytic gradient is based on Variational Quantum Imaginary…

Quantum Physics · Physics 2021-03-01 Christa Zoufal , Aurélien Lucchi , Stefan Woerner

Many-body quantum systems in nonequilibrium remain one of the frontiers of many-body physics. While there has been significant advances in describing the short-time evolution of these systems using a variety of different numerical…

Quantum Physics · Physics 2021-01-05 Herbert F. Fotso , Eric Dohner , Alexander Kemper , James K. Freericks

Time-resolved spectroscopy is a powerful tool for probing electron dynamics in molecules and solids, revealing transient phenomena on sub-femtosecond timescales. The interpretation of experimental results is often enhanced by parallel…

Computational Physics · Physics 2025-05-02 Cian Reeves , Michael Kurniawan , Yuanran Zhu , Nikil Jampana , Jacob Brown , Chao Yang , Khaled Ibrahim , Vojtech Vlcek

We digitally simulate quantum many-body dynamics in emergent curved backgrounds using 80 superconducting qubits on IBM Heron processors. By engineering spatially varying couplings in the spin-$\frac12$ XXZ chain, consistent with the…

We propose an improved quantum algorithm to calculate the Green's function through real-time propagation, and use it to compute the retarded Green's function for the 2-, 3- and 4-site Hubbard models. This novel protocol significantly…

Quantum Physics · Physics 2022-10-21 Francesco Libbi , Jacopo Rizzo , Francesco Tacchino , Nicola Marzari , Ivano Tavernelli

The continued development of computational approaches to many-body ground-state problems in physics and chemistry calls for a consistent way to assess its overall progress. In this work, we introduce a metric of variational accuracy, the…

Quantum many-body control is among most challenging problems in quantum science, due to computational complexity of related underlying problems. We propose an efficient approach for solving a class of control problems for many-body quantum…

Quantum Physics · Physics 2024-02-21 I. A. Luchnikov , M. A. Gavreev , A. K. Fedorov

Quantum simulators have made a remarkable progress towards exploring the dynamics of many-body systems, many of which offer a formidable challenge to both theoretical and numerical methods. While state-of-the-art quantum simulators are in…