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Related papers: Quantum Critical Points and the Sign Problem

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Studying strong electron correlations has been an essential driving force for pushing the frontiers of condensed matter physics. In particular, in the vicinity of correlation-driven quantum phase transitions (QPTs), quantum critical…

We introduce a Quantum Monte Carlo (QMC) method which efficiently simulates in a sign-problem-free way a broad class of frustrated $S=1/2$ models with competing antiferromagnetic interactions. Our scheme uses the basis of total spin…

Strongly Correlated Electrons · Physics 2016-11-09 Fabien Alet , Kedar Damle , Sumiran Pujari

In this work, we initiate the study of the Minimum Circuit Size Problem (MCSP) in the quantum setting. MCSP is a problem to compute the circuit complexity of Boolean functions. It is a fascinating problem in complexity theory -- its…

Quantum Physics · Physics 2021-09-15 Nai-Hui Chia , Chi-Ning Chou , Jiayu Zhang , Ruizhe Zhang

The emergence of a collective behavior in a many-body system is responsible of the quantum criticality separating different phases of matter. Interacting spin systems in a magnetic field offer a tantalizing opportunity to test different…

Quantum Physics · Physics 2023-02-17 Michele Grossi , Oriel Kiss , Francesco De Luca , Carlo Zollo , Ian Gremese , Antonio Mandarino

We illustrate the application of Quantum Computing techniques to the investigation of the thermodynamical properties of a simple system, made up of three quantum spins with frustrated pair interactions and affected by a hard sign problem…

Deconfined quantum critical point (DQCP) characterizes the continuous transition beyond Landau-Ginzburg-Wilson paradigm, occurring between two phases that exhibit distinct symmetry breaking. The debate over whether genuine DQCP exists in…

Strongly Correlated Electrons · Physics 2025-11-06 Xuan Zou , Shuai Yin , Zi-Xiang Li , Hong Yao

We propose a projection approach to perform quantum Monte Carlo (QMC) simulation on the infinite-$U$ Hubbard model at some integer fillings where either it is sign problem free or surprisingly has an algebraic sign structure -- a power law…

Strongly Correlated Electrons · Physics 2021-12-28 Yunqing Ouyang , Xiao Yan Xu

We report on the new non--linear optical signatures of quantum phase transitions in the high-temperature superconductor YBCO, observed through high harmonic generation. While the linear optical response of the material is largely unchanged…

We describe an approach for many-body calculations with a finite-temperature, grand canonical ensemble formalism using auxiliary-field quantum Monte Carlo (AFQMC) with a self-consistent constraint to control the sign problem. The usual…

Strongly Correlated Electrons · Physics 2019-06-18 Yuan-Yao He , Mingpu Qin , Hao Shi , Zhong-Yi Lu , Shiwei Zhang

Recently, in high-T_c superconductors (HTSC), exciting measurements have been performed revealing their physics in superconducting and pseudogap states and in normal one induced by the application of magnetic field, when the transition from…

Superconductivity · Physics 2009-02-17 V. R. Shaginyan , M. Ya. Amusia , K. G. Popov , V. A. Stephanovich

I review recent developments in determining the QCD phase diagram by means of lattice simulations. Since the invention of methods to side-step the sign problem a few years ago, a number of additional variants have been proposed, and…

High Energy Physics - Lattice · Physics 2007-05-23 Owe Philipsen

Quantum Monte Carlo methods are powerful tools for studying quantum many-body systems but face difficulties in accessing excited states and in treating sign problems. We present a continuous-time path-integral Monte Carlo method for…

Strongly Correlated Electrons · Physics 2025-12-16 Abhishek Karna , Hansen S. Wu , Shailesh Chandrasekharan , Ribhu K. Kaul

The main objective of quantum simulation is an in-depth understanding of many-body physics. It is important for fundamental issues (quantum phase transitions, transport, . . . ) and for the development of innovative materials. Analytic…

The Monte Carlo evaluation of path integrals is one of a few general purpose methods to approach strongly coupled systems. It is used in all branches of Physics, from QCD/nuclear physics to the correlated electron systems. However, many…

High Energy Physics - Lattice · Physics 2020-07-13 Andrei Alexandru , Gokce Basar , Paulo F. Bedaque , Neill C. Warrington

We derive the primitive quantum gate sets to simulate lattice quantum chromodynamics (LQCD) in the strong-coupling limit with one flavor of massless staggered quarks. This theory is of interest for studies at non-zero density as the sign…

High Energy Physics - Lattice · Physics 2025-08-20 Michael Fromm , Owe Philipsen , Wolfgang Unger , Christopher Winterowd

We consider quantum critical points (QCP) in which quantum fluctuations associated with charge rather than magnetic order induce unconventional metallic properties. Based on finite-T calculations on a two-dimensional extended Hubbard model…

Strongly Correlated Electrons · Physics 2015-05-18 Laura Cano-Cortes , Jaime Merino , Simone Fratini

This review summarizes recent developments in the study of fermionic quantum criticality, focusing on new progress in numerical methodologies, especially quantum Monte Carlo methods, and insights that emerged from recently large-scale…

Strongly Correlated Electrons · Physics 2019-09-10 Xiao Yan Xu , Zi Hong Liu , Gaopei Pan , Yang Qi , Kai Sun , Zi Yang Meng

Accurate thermodynamic simulations of correlated fermions using path integral Monte Carlo (PIMC) methods are of paramount importance for many applications such as the description of ultracold atoms, electrons in quantum dots, and warm-dense…

Computational Physics · Physics 2021-02-03 Tobias Dornheim , Michele Invernizzi , Jan Vorberger , Barak Hirshberg

Here we develop a new scheme of projective quantum Monte-Carlo (QMC) simulation combining unbiased zero-temperature (projective) determinant QMC and variational Monte-Carlo based on Gutzwiller projection wave function, dubbed as…

Strongly Correlated Electrons · Physics 2026-04-08 Wei-Xuan Chang , Zi-Xiang Li

Quantum simulation uses a well-known quantum system to predict the behavior of another quantum system. Certain limitations in this technique arise, however, when applied to specific problems, as we demonstrate with a theoretical and…

Quantum Physics · Physics 2009-11-13 Kenneth R. Brown , Robert J. Clark , Isaac L. Chuang
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