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This note starts with a recapitulation of what people call the ``Measurement Problem'' of Quantum Mechanics (QM). The dissipative nature of the quantum-mechanical time-evolution of averages of states over large ensembles of identical…

Quantum Physics · Physics 2026-03-27 Jürg Fröhlich , Alessandro Pizzo

The real- and imaginary-time evolution of quantum states are powerful tools in physics, chemistry, and beyond, to investigate quantum dynamics, prepare ground states or calculate thermodynamic observables. On near-term devices, variational…

Quantum Physics · Physics 2024-02-27 Julien Gacon , Jannes Nys , Riccardo Rossi , Stefan Woerner , Giuseppe Carleo

Recent experiments with quantum simulators using ultracold atoms and superconducting qubits have demonstrated the potential of controlled dissipation as a versatile tool for realizing correlated many-body states. However, determining the…

The accurate solution of dissipative quantum dynamics plays an important role on the simulation of open quantum systems. Here we propose a machine-learning-based universal solver for the hierarchical equations of motion, one of the most…

Chemical Physics · Physics 2026-05-19 Jiaji Zhang , Lipeng Chen

We study under which conditions an overdamped regime can be attained in the dynamic evolution of a quantum field configuration. Using a real-time formulation of finite temperature field theory, we compute the effective evolution equation of…

High Energy Physics - Phenomenology · Physics 2011-05-05 Arjun Berera , Marcelo Gleiser , Rudnei O. Ramos

In a recent paper, Hassoul et al.[1], the authors proposed an analysis of the quantum dynamics for general time-dependent three coupled oscillators through an approach based on their decouplement using the unitary transformation method.…

Quantum Physics · Physics 2022-09-27 Zerimeche Rahma , Mana Naima , Maamache Mustapha

This work discusses a variational approach to determining the time evolution operator. We directly see a glimpse of how a generalization of the quantum geometric tensor for unitary operators plays a central role in parameter evolution. We…

Quantum Physics · Physics 2025-04-15 Michael Vogl

We propose a method to simulate the real time evolution of one dimensional quantum many-body systems at finite temperature by expressing both the density matrices and the observables as matrix product states. This allows the calculation of…

Quantum Physics · Physics 2014-07-16 Iztok Pizorn , Viktor Eisler , Sabine Andergassen , Matthias Troyer

The current generation of noisy intermediate scale quantum computers introduces new opportunities to study quantum many-body systems. In this paper, we show that quantum circuits can provide a dramatically more efficient representation than…

Quantum Physics · Physics 2021-03-24 Sheng-Hsuan Lin , Rohit Dilip , Andrew G. Green , Adam Smith , Frank Pollmann

This manuscript aims to illustrate a quantum-classical dissipative theory (suited to be converted to effective algorithms for numerical simulations) within the long-term project of studying molecular processes in the brain. Other…

Neurons and Cognition · Quantitative Biology 2025-03-04 Alessandro Sergi , Antonino Messina , Rosalba Saija , Gabriella Martino , Maria Teresa Caccamo , Min-Fang Kuo , Michael A. Nitsche

We derive an exact equation of motion for the reduced density matrices of individual subsystems of quantum many-body systems of any lattice dimension and arbitrary system size. Our projection operator based theory yields a highly efficient…

Quantum Physics · Physics 2014-06-13 Peter Degenfeld-Schonburg , Michael J. Hartmann

We introduce a type of quantum dissipation -- local quantum friction -- by adding to the Hamiltonian a local potential that breaks time-reversal invariance so as to cool the system. Unlike the Kossakowski-Lindblad master equation, local…

Nuclear Theory · Physics 2013-05-30 Aurel Bulgac , Michael McNeil Forbes , Kenneth J. Roche , Gabriel Wlazłowski

Certain aspects of some unitary quantum systems are well-described by evolution via a non-Hermitian effective Hamiltonian, as in the Wigner-Weisskopf theory for spontaneous decay. Conversely, any non-Hermitian Hamiltonian evolution can be…

High Energy Physics - Lattice · Physics 2021-12-01 Jay Hubisz , Bharath Sambasivam , Judah Unmuth-Yockey

Variational quantum algorithms have been proposed to solve static and dynamic problems of closed many-body quantum systems. Here we investigate variational quantum simulation of three general types of tasks---generalised time evolution with…

Quantum Physics · Physics 2020-07-01 Suguru Endo , Jinzhao Sun , Ying Li , Simon Benjamin , Xiao Yuan

We present a numerical method to simulate the dynamics of continuous-variable quantum many-body systems. Our approach is based on custom neural-network many-body quantum states. We focus on dynamics of two-dimensional quantum rotors and…

Quantum Physics · Physics 2023-10-12 Matija Medvidović , Dries Sels

A variety of dynamics in nature and society can be approximately treated as a driven and damped parametric oscillator. An intensive investigation of this time-dependent model from an algebraic point of view provides a consistent method to…

Quantum Physics · Physics 2016-08-24 Lin Zhang , Weiping Zhang

Two-time correlations are a crucial tool to probe the dynamics of many-body systems. We use these correlation functions to study the dynamics of dissipative quantum systems. Extending the adiabatic elimination method, we show that the…

Quantum Gases · Physics 2015-06-11 Bruno Sciolla , Dario Poletti , Corinna Kollath

In this series of works, we study exactly solvable non-unitary time evolutions in one-dimensional quantum critical systems ranging from quantum quenches to time-dependent drivings. In this part I, we are motivated by the recent works of…

Statistical Mechanics · Physics 2024-10-30 Xueda Wen

We develop a real-time Full Configuration Interaction Quantum Monte Carlo approach for the modeling of driven-dissipative open quantum systems. The method enables stochastic sampling of the Liouville-von-Neumann time evolution of the…

Quantum Physics · Physics 2018-06-06 Alexandra Nagy , Vincenzo Savona

We study the nonequilibrium dynamics of a many-body bosonic system on a lattice, subject to driving and dissipation. The time-evolution is described by a master equation, which we treat within a generalized Gutzwiller mean field…

Quantum Gases · Physics 2013-05-29 Andrea Tomadin , Sebastian Diehl , Peter Zoller