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We derive equations of motion for Green's functions of the multi-orbital Anderson impurity model by differentiating symmetrically with respect to all time arguments. The resulting equations relate the one- and two-particle Green's function…

Strongly Correlated Electrons · Physics 2019-08-14 Josef Kaufmann , Patrik Gunacker , Alexander Kowalski , Giorgio Sangiovanni , Karsten Held

We propose a mixed quantum-classical hydrodynamic framework to model short-time inertial effects in the non-adiabatic evolution of a quantum solute coupled to a classical polar solvent. Drawing upon the work of Burghardt and Bagchi [Chem.…

Chemical Physics · Physics 2026-05-22 François Gay-Balmaz , Cesare Tronci

The developments of quantum computing algorithms and experiments for atomic scale simulations have largely focused on quantum chemistry for molecules, while their application in condensed matter systems is scarcely explored. Here we present…

A Monte Carlo method is presented to evaluate quantum states with many particles moving in the continuum. The scattering state is generated at each time by a Monte Carlo random sampling algorithm. The same calculation are repeated until the…

Nuclear Theory · Physics 2013-06-06 Zhen-Xiang Xu , Chong Qi

We have investigated the finite temperature dynamics of the singlet to doublet continuous quantum phase transition in the gapped Anderson impurity model using hybridization expansion continuous time quantum Monte-Carlo. Using the…

Strongly Correlated Electrons · Physics 2015-12-03 Nagamalleswararao Dasari , Swagata Acharya , A. Taraphder , Juana Moreno , Mark Jarrell , N. S. Vidhyadhiraja

We propose a novel approach to qubit thermometry using a quantum switch, that introduces an indefinite causal order in the probe-bath interaction, to significantly enhance the thermometric precision. The resulting qubit probe shows improved…

Quantum Physics · Physics 2018-12-19 Chiranjib Mukhopadhyay , Manish K. Gupta , Arun Kumar Pati

A method is presented to tackle the sign problem in the simulations of systems having indefinite or complex-valued measures. In general, this new approach is shown to yield statistical errors smaller than the crude Monte Carlo using…

High Energy Physics - Lattice · Physics 2008-11-26 T D Kieu , C J Griffin

We study the real-time dynamics of quantum models with long-range interactions coupled to a heat-bath within the closed-time path-integral formalism. We show that quantum fluctuations depress the transition temperature. In the subcritical…

Condensed Matter · Physics 2009-10-30 Leticia F. Cugliandolo , Gustavo Lozano

The path integral formalism is the building block of many powerful numerical methods for quantum impurity problems. However, existing fermionic path integral based numerical calculations have only been performed in either the imaginary-time…

Strongly Correlated Electrons · Physics 2024-10-10 Ruofan Chen , Chu Guo

We present a quantum Monte Carlo method capable of sampling the full density matrix of a many-particle system at finite temperature. This allows arbitrary reduced density matrix elements and expectation values of complicated non-local…

Computational Physics · Physics 2015-06-15 N. S. Blunt , T. W. Rogers , J. S. Spencer , W. M. C. Foulkes

We implement the recently developed influence functional matrix product states approach as impurity solver in equilibrium and nonequilibrium dynamical mean field theory (DMFT) calculations of the single-band Hubbard model. The method yields…

Strongly Correlated Electrons · Physics 2025-07-02 Mithilesh Nayak , Julian Thoenniss , Michael Sonner , Dmitry A. Abanin , Philipp Werner

A simple impurity solver is shown to capture the impurity-induced superconducting subgap states in quantitative agreement with the numerical renormalization group and quantum Monte-Carlo simulations. The solver is based on the exact…

Superconductivity · Physics 2023-12-21 Virgil V. Baran , Emil J. P. Frost , Jens Paaske

The quantum speed limit (QSL) provides a fundamental upper bound on the speed of quantum evolution, but its evaluation in generic open quantum systems still presents a formidable computational challenge. Herein, we introduce a hybrid…

Quantum Physics · Physics 2019-04-30 Junjie Liu , Dvira Segal , Gabriel Hanna

We analyse the evolution of a quantum oscillator in a finite temperature environment using the quantum state diffusion (QSD) picture. Following a treatment similar to that of reference [7] we identify stationary solutions of the…

Quantum Physics · Physics 2009-10-28 Andreas Zoupas

The cavity method is a well established technique for solving classical spin models on sparse random graphs (mean-field models with finite connectivity). Laumann et al. [arXiv:0706.4391] proposed recently an extension of this method to…

Statistical Mechanics · Physics 2009-11-13 Florent Krzakala , Alberto Rosso , Guilhem Semerjian , Francesco Zamponi

We present a unified approach to study continuous measurement based quantum thermal machines in static as well as adiabatically driven systems. We investigate both steady state and transient dynamics for the time-independent case. In the…

Quantum Physics · Physics 2022-08-11 Bibek Bhandari , Andrew N. Jordan

Determining ground state energies of quantum systems by hybrid classical/quantum methods has emerged as a promising candidate application for near-term quantum computational resources. Short of large-scale fault-tolerant quantum computers,…

Quantum Physics · Physics 2016-10-25 Nicholas C. Rubin

Direct sampling of multi-dimensional systems with quantum Monte Carlo methods allows exact account of many-body effects or particle correlations. The most straightforward approach to solve the Schr\"odinger equation, Diffusion Monte Carlo,…

Quantum Physics · Physics 2017-09-07 Ilkka Ruokosenmäki , Tapio T. Rantala

There is presently considerable interest in accurately simulating the evolution of open systems for which Markovian master equations fail. Examples are systems that are time-dependent and/or strongly damped. A number of elegant methods have…

Quantum Physics · Physics 2014-04-23 Luciano Silvestri , Kurt Jacobs , Vanja Dunjko , Maxim Olshanii

We present a minimally entangled typical thermal state (METTS) quantum impurity solver for general multi-orbital systems at finite temperatures. We introduce an improved estimator for the single-particle Green's function that strongly…

Strongly Correlated Electrons · Physics 2024-08-26 Xiaodong Cao , E. Miles Stoudenmire , Olivier Parcollet