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We develop a numerical method to compute the negativity, an entanglement measure for mixed states, between the impurity and the bath in quantum impurity systems at finite temperature. We construct a thermal density matrix by using the…

Mesoscale and Nanoscale Physics · Physics 2018-08-28 Jeongmin Shim , H. -S. Sim , Seung-Sup B. Lee

Solving the Anderson impurity model typically involves a two-step process, where one first calculates the ground state of the Hamiltonian, and then computes its dynamical properties to obtain the Green's function. Here we propose a hybrid…

Systems of correlated quantum matter can be a steep challenge to any would-be method of solution. Matrix-product state (MPS)-based methods can describe 1D systems quasiexactly, but often struggle to retain sufficient bipartite entanglement…

Strongly Correlated Electrons · Physics 2024-11-04 Gunnar Bollmark , Sam Mardazad , Johannes S. Hofmann , Adrian Kantian

A continuous-time path integral Quantum Monte Carlo method using the directed-loop algorithm is developed to simulate the Anderson single-impurity model in the occupation number basis. Although the method suffers from a sign problem at low…

Strongly Correlated Electrons · Physics 2009-11-10 Jaebeom Yoo , Shailesh Chandrasekharan , Harold U. Baranger

The matrix product state (MPS) is utilized to study the ground state properties and quantum phase transitions (QPTs) of the one-dimensional quantum compass model (QCM). The MPS wavefunctions are argued to be very efficient descriptions of…

Strongly Correlated Electrons · Physics 2012-06-05 Guang-Hua Liu , Wei Li , Wen-Long You , Guang-Shan Tian , Gang Su

Quantum impurities can host exotic many-body states that serve as sensitive probes of bath correlations. However, quantitative and non-perturbative methods for determining impurity thermodynamics in such settings remain scarce. Here, we…

Strongly Correlated Electrons · Physics 2026-01-09 Tao Yang , Z. Y. Xie , Rui Wang , Baigeng Wang

Quantum impurity models are prevalent throughout many body physics, providing some prime examples of strongly correlated systems. Aside from being of great interest in themselves they can provide deep insight into the effects of strong…

Strongly Correlated Electrons · Physics 2020-01-08 Parameshwar R. Pasnoori , Colin Rylands , Natan Andrei

We consider quantum entanglement in strongly correlated quantum impurity systems for states manifesting interesting properties such as multi-level Kondo effect and dual nature between itineracy and localization etc.. For this purpose, we…

Strongly Correlated Electrons · Physics 2025-04-03 Yunori Nishikawa , Tomoki Yoshioka

The relation between entanglement entropy and the computational difficulty of classically simulating Quantum Mechanics is briefly reviewed. Matrix product states are proven to provide an efficient representation of one-dimensional quantum…

Quantum Physics · Physics 2008-11-26 Jose I. Latorre

We use the time dependent variational matrix product state (tVMPS) approach to investigate the dynamical properties of the single impurity Anderson model (SIAM). Under the Jordan-Wigner transformation, the SIAM is reformulated into two…

Strongly Correlated Electrons · Physics 2010-02-04 Lei Wang , Jia-Ning Zhuang , Xi Dai , X. C. Xie

We consider the Hubbard model with a magnetic Anderson impurity coupled to a lattice site. In the case of infinite dimensions, one-particle correlations of the impurity electron are described by the effective Hamiltonian of the two-impurity…

Strongly Correlated Electrons · Physics 2009-10-30 Benny Davidovich , V. Zevin

Sampling problems have emerged as a central avenue for demonstrating quantum advantage on noisy intermediate-scale quantum devices. However, physical noise can fundamentally alter their computational complexity, often making them…

Quantum Physics · Physics 2025-11-07 Sojeong Park , Changhun Oh

We study equilibrium and nonequilibrium properties of the single-impurity Anderson model with a power-law pseudogap in the density of states. In equilibrium, the model is known to display a quantum phase transition from a generalized Kondo…

Strongly Correlated Electrons · Physics 2020-04-29 Delia M. Fugger , Daniel Bauernfeind , Max E. Sorantin , Enrico Arrigoni

Encoding classical data in a quantum state is a key prerequisite of many quantum algorithms. Recently matrix product state (MPS) methods emerged as the most promising approach for constructing shallow quantum circuits approximating input…

Solving quantum many-body systems is one of the most significant regimes where quantum computing applies. Currently, as a hardware-friendly computational paradigms, variational algorithms are often used for finding the ground energy of…

Quantum Physics · Physics 2026-02-10 Yong Liu , Guangyao Huang , Yizhi Wang , Junjie Wu

An Anderson impurity in a Hubbard model on chains with finite length is studied using the density-matrix renormalization group (DMRG) technique. In the first place, we analyzed how the reduction of electron density from half-filling to…

Strongly Correlated Electrons · Physics 2009-11-11 S. Costamagna , C. J. Gazza , M. E. Torio , J. A. Riera

We develop a numerical method based on matrix product states for simulating quantum many-body systems at finite temperatures without importance sampling and evaluate its performance in spin 1/2 systems. Our method is an extension of the…

Strongly Correlated Electrons · Physics 2021-07-27 Shimpei Goto , Ryui Kaneko , Ippei Danshita

We simulate the nonequilibrium dynamics of two generic many-body quantum impurity models by employing the recently developed iterative influence-functional path integral method [Phys. Rev. B {\bf 82}, 205323 (2010)]. This general approach…

Mesoscale and Nanoscale Physics · Physics 2017-09-13 Dvira Segal , Andrew J. Millis , David R. Reichman

We introduce a numerically exact real-time evolution scheme for quantum impurities in a macroscopically large bath. The algorithm is few-body revealing, namely it identifies the electronic orbitals that can be made inactive (in a trivial…

Strongly Correlated Electrons · Physics 2025-09-26 Yuriel Núñez-Fernández , Maxime Debertolis , Serge Florens

Matrix product states provide a natural entanglement basis to represent a quantum register and operate quantum gates on it. This scheme can be materialized to simulate a quantum adiabatic algorithm solving hard instances of a NP-Complete…

Quantum Physics · Physics 2009-11-11 M. C. Banuls , R. Orus , J. I. Latorre , A. Perez , P. Ruiz-Femenia