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We develop an efficient variational approach to studying dynamics of a localized quantum spin coupled to a bath of mobile spinful bosons. We use parity symmetry to decouple the impurity spin from the environment via a canonical…

Strongly Correlated Electrons · Physics 2019-11-04 Yuto Ashida , Tao Shi , Richard Schmidt , H. R. Sadeghpour , J. Ignacio Cirac , Eugene Demler

We introduce a variational approach for preparing low energy states of arbitrary target Hamiltonians. The protocol is defined in terms of a repeated cycle consisting of p layers of unitary gates applied to the system and ancilla "bath"…

Quantum Physics · Physics 2025-10-14 Jeffrey Z. Song , Gilad Kishony , Erez Berg , Mark S. Rudner

The cluster variation method (CVM) is a hierarchy of approximate variational techniques for discrete (Ising--like) models in equilibrium statistical mechanics, improving on the mean--field approximation and the Bethe--Peierls approximation,…

Statistical Mechanics · Physics 2007-07-16 Alessandro Pelizzola

The coherent potential approximation (CPA) is extended to describe satisfactorily the motion of particles in a random potential which is spatially correlated and smoothly varying. In contrast to existing cluster-CPA methods, the present…

Disordered Systems and Neural Networks · Physics 2009-10-20 Roland Zimmermann , Christoph Schindler

Clustering algorithms are fundamental tools across many fields, with density-based methods offering particular advantages in identifying arbitrarily shaped clusters and handling noise. However, their effectiveness is often limited by the…

Machine Learning · Computer Science 2025-12-01 Meysam Shirdel Bilehsavar , Razieh Ghaedi , Samira Seyed Taheri , Xinqi Fan , Christian O'Reilly

We consider an integrable model describing an Anderson-like impurity coupled to an open $t$--$J$ chain. Both the hybridization (i.e. its coupling to bulk chain) and the local spectrum can be controlled without breaking the integrability of…

Strongly Correlated Electrons · Physics 2007-05-23 Holger Frahm , Guillaume Palacios

Recently the authors developed a scattering approach that allows for a complete description of the steady-state physics of quantum-impurities in and out of equilibrium. Quantum impurities are described using scattering eigenstates defined…

Strongly Correlated Electrons · Physics 2007-05-23 Pankaj Mehta , Natan Andrei

Subject clustering (i.e., the use of measured features to cluster subjects, such as patients or cells, into multiple groups) is a problem of great interest. In recent years, many approaches were proposed, among which unsupervised deep…

Methodology · Statistics 2023-06-09 Dieyi Chen , Jiashun Jin , Zheng Tracy Ke

A central feature of the Periodic Anderson Model is the competition between antiferromagnetism, mediated by the Ruderman-Kittel-Kasuya-Yosida interaction at small conduction electron-local electron hybridization $V$, and singlet formation…

Strongly Correlated Electrons · Physics 2016-08-24 Ali Benali , Zhaojun Bai , Nicholas J. Curro , Richard T. Scalettar

This paper presents a new approach to non-parametric cluster analysis called Adaptive Weights Clustering (AWC). The idea is to identify the clustering structure by checking at different points and for different scales on departure from…

Machine Learning · Statistics 2017-09-27 Kirill Efimov , Larisa Adamyan , Vladimir Spokoiny

The method of continuous unitary transformations (CUTs) is applied to the Anderson impurity and the Kondo model aiming at the systematic derivation of convergent effective models. If CUTs are applied in a conventional way, diverging…

Strongly Correlated Electrons · Physics 2015-03-03 Jörn Krones , Götz S. Uhrig

We propose a hierarchical dynamics approach for evaluation of nonequilibrium dynamic response properties of quantum impurity systems. It is based on a hierarchical equations of motion formalism, in conjunction with a linear response theory…

Strongly Correlated Electrons · Physics 2013-07-15 Shikuan Wang , Xiao Zheng , Jinshuang Jin , YiJing Yan

The accurate determination of the electronic structure of strongly correlated materials using first principle methods is of paramount importance in condensed matter physics, computational chemistry, and material science. However, due to the…

The development of numerical methods capable of simulating realistic materials with strongly correlated electrons, with controllable errors, is a central challenge in quantum many-body physics. Here we describe how a hybrid between…

Strongly Correlated Electrons · Physics 2015-04-23 Alexei A. Kananenka , Emanuel Gull , Dominika Zgid

A weakly supervised learning based clustering framework is proposed in this paper. As the core of this framework, we introduce a novel multiple instance learning task based on a bag level label called unique class count ($ucc$), which is…

Computer Vision and Pattern Recognition · Computer Science 2020-01-28 Mustafa Umit Oner , Hwee Kuan Lee , Wing-Kin Sung

While limited coupled cluster theory is \textit{formally} nonvariational, it is not broadly appreciated whether this is a major issue \textit{in practice}. We carried out a detailed comparison with \textit{de facto} full CI energies for a…

Chemical Physics · Physics 2024-10-03 Jan M. L. Martin , Emmanouil Semidalas

We develop a technique for probing harmonic measure of the diffusion limited aggregation (DLA) cluster surface with the variable size particle and generate one thousand clusters with 50 million particles using original off-lattice…

Disordered Systems and Neural Networks · Physics 2007-05-23 A. Yu. Menshutin , L. N. Shchur , V. M. Vinokur

We introduce a `virtual-move' Monte Carlo (VMMC) algorithm for systems of pairwise-interacting particles. This algorithm facilitates the simulation of particles possessing attractions of short range and arbitrary strength and geometry, an…

Statistical Mechanics · Physics 2009-11-11 Stephen Whitelam , Phillip L. Geissler

We analyze the process of thermalization, dynamics and the eigenstate thermalization hypothesis (ETH) for the single impurity Anderson model, focusing on the Kondo regime. For this we construct the complete eigenbasis of the Hamiltonian…

Mesoscale and Nanoscale Physics · Physics 2017-08-23 I. Weymann , J. von Delft , A. Weichselbaum

We investigate the cluster size convergence of the energy and observables using two forms of density matrix embedding theory (DMET): the original cluster form (CDMET) and a new formulation motivated by the dynamical cluster approximation…

Strongly Correlated Electrons · Physics 2017-01-11 Bo-Xiao Zheng , Joshua S. Kretchmer , Hao Shi , Shiwei Zhang , Garnet Kin-Lic Chan