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We have used the variational and diffusion quantum Monte Carlo methods to calculate the energy, pair correlation function, static structure factor, and momentum density of the ground state of the two-dimensional homogeneous electron gas. We…

Mesoscale and Nanoscale Physics · Physics 2010-03-02 N. D. Drummond , R. J. Needs

High-quality random samples of quantum states are needed for a variety of tasks in quantum information and quantum computation. Searching the high-dimensional quantum state space for a global maximum of an objective function with many local…

Quantum Physics · Physics 2015-04-28 Yi-Lin Seah , Jiangwei Shang , Hui Khoon Ng , David John Nott , Berthold-Georg Englert

We present a numerical quantum Monte Carlo (QMC) method for simulating the 3D phase transition on the recently proposed fuzzy sphere [Phys. Rev. X 13, 021009 (2023)]. By introducing an additional $SU(2)$ layer degree of freedom, we…

Strongly Correlated Electrons · Physics 2024-06-26 Johannes S. Hofmann , Florian Goth , Wei Zhu , Yin-Chen He , Emilie Huffman

We analyze the scaling parameter, extracted from the fidelity for two different ground states, for the one-dimensional quantum Ising model in a transverse field near the critical point. It is found that, in the thermodynamic limit, the…

Statistical Mechanics · Physics 2009-11-13 Huan-Qiang Zhou , Jian-Hui Zhao , Bo Li

Quantum Monte Carlo methods are used to study a quantum phase transition in a 1D Hubbard model with a staggered ionic potential (D). Using recently formulated methods, the electronic polarization and localization are determined directly…

Strongly Correlated Electrons · Physics 2009-10-31 Tim Wilkens , Richard M. Martin

In this paper, we explore the differences between classical logarithmic fidelity and quantum fidelity. The classical logarithmic fidelity is found to be always extensive while the quantum one manifests distinct size dependence in different…

Statistical Mechanics · Physics 2016-12-23 Ching-Yee Leung , Ho-Man Kwok , Shi-Jian Gu , Hai-Qing Lin

A numerically implementable Multi-scale Many-Body approach to strongly correlated electron systems is introduced. An extension to quantum cluster methods, it approximates correlations on any given length-scale commensurate with the strength…

Strongly Correlated Electrons · Physics 2012-01-04 C. Slezak , M. Jarrell , Th. Maier , J. Deisz

The quantum Monte Carlo (QMC) is one of the most promising many-body electronic structure approaches. It employs stochastic techniques for solving the stationary Schr\" odinger equation and for evaluation of expectation values. The key…

Other Condensed Matter · Physics 2007-12-20 Michal Bajdich

We study the three-dimensional (3D) attractive Hubbard model by means of the Determinant Quantum Monte Carlo method. This model is a prototype for the description of the smooth crossover between BCS superconductivity and Bose-Einstein…

Condensed Matter · Physics 2009-11-07 A. Sewer , X. Zotos , H. Beck

Compact and accurate wave functions can be constructed by quantum Monte Carlo methods. Typically, these wave functions consist of a sum of a small number of Slater determinants multiplied by a Jastrow factor. In this paper we study the…

Condensed Matter · Physics 2009-10-30 Chien-Jung Huang , C. J. Umrigar , M. P. Nightingale

In this article we present the second part of our historical survey on quantum Monte Carlo methods. IWe focus on the simulations performed at a finite temperature and based on the path-integral formulation of quantum mechanics. We introduce…

History and Philosophy of Physics · Physics 2021-09-29 Michel Mareschal

We characterize excited state quantum phase transitions in the two dimensional limit of the vibron model with the quantum fidelity susceptibility, comparing the obtained results with the information provided by the participation ratio. As…

Quantum Physics · Physics 2022-01-05 J. Khalouf-Rivera , M. Carvajal , F. Pérez-Bernal

We propose an efficient method for Monte Carlo simulation of quantum lattice models. Unlike most other quantum Monte Carlo methods, a single run of the proposed method yields the free energy and the entropy with high precision for the whole…

Statistical Mechanics · Physics 2009-11-10 Chiaki Yamaguchi , Naoki Kawashima , Yutaka Okabe

We consider a two-dimensional quantum spin system described by a Heisenberg model that is embedded in a three-dimensional metal. The two systems couple via an antiferromagnetic Kondo interaction. In such a setup, the ground state…

Strongly Correlated Electrons · Physics 2023-10-10 Zi Hong Liu , Bernhard Frank , Lukas Janssen , Matthias Vojta , Fakher F. Assaad

We use reduced fidelity approach to characterize quantum phase transitions in the one-dimensional spin-1/2 dimerized Heisenberg chain in the antiferromagnetic case. The reduced fidelity susceptibilities between two nearest-neighboring spin…

Quantum Physics · Physics 2009-11-13 Heng-Na Xiong , Jian Ma , Zhe Sun , Xiaoguang Wang

We use the fidelity approach to quantum critical points to study the zero temperature phase diagram of the one-dimensional Hubbard model. Using a variety of analytical and numerical techniques, we analyze the fidelity metric in various…

Statistical Mechanics · Physics 2009-11-13 L. Campos Venuti , M. Cozzini , P. Buonsante , F. Massel , N. Bray-Ali , P. Zanardi

In many-body quantum systems, the quantum Fisher information an observer can obtain is susceptible to decoherence. Consequently, quantum enhanced metrology, such as Heisenberg scaling, cannot usually be achieved. We show, via two distinct…

Quantum Physics · Physics 2022-12-06 Le Hu , Shengshi Pang , Andrew Jordan

Modeling the dynamics of a quantum system connected to the environment is critical for advancing our understanding of complex quantum processes, as most quantum processes in nature are affected by an environment. Modeling a macroscopic…

Quantum phase transitions in many-body systems are fundamentally characterized by complex correlation structures, which pose computational challenges for conventional methods in large systems. To address this, we propose a hybrid…

Quantum Physics · Physics 2026-02-03 Jin-Long Chen , Xin Li , Zhang-Qi Yin

A $\theta$ term, which couples to topological charge, is added to the two-dimensional lattice CP^3 model and U(1) gauge theory. Monte Carlo simulations are performed and compared to strong-coupling character expansions. In certain…

High Energy Physics - Lattice · Physics 2009-10-30 Jan C. Plefka , Stuart Samuel