English
Related papers

Related papers: Simpler (classical) and faster (quantum) algorithm…

200 papers

A linear-time algorithm is presented for the construction of the Gibbs distribution of configurations in the Ising model, on a quantum computer. The algorithm is designed so that each run provides one configuration with a quantum…

Quantum Physics · Physics 2009-10-30 Daniel A. Lidar , Ofer Biham

We establish a polynomial-time approximation algorithm for partition functions of quantum spin models at high temperature. Our algorithm is based on the quantum cluster expansion of Neto\v{c}n\'y and Redig and the cluster expansion approach…

Data Structures and Algorithms · Computer Science 2021-02-02 Ryan L. Mann , Tyler Helmuth

Learning the Hamiltonian underlying a quantum many-body system in thermal equilibrium is a fundamental task in quantum learning theory and experimental sciences. To learn the Gibbs state of local Hamiltonians at any inverse temperature…

Quantum Physics · Physics 2025-04-04 Chi-Fang Chen , Anurag Anshu , Quynh T. Nguyen

Recent technological developments have focused the interest of the quantum computing community on investigating how near-term devices could outperform classical computers for practical applications. A central question that remains open is…

Quantum Physics · Physics 2021-11-24 Daniel Stilck Franca , Raul Garcia-Patron

A quantum system coupled to a bath at some fixed, finite temperature converges to its Gibbs state. This thermalization process defines a natural, physically-motivated model of quantum computation. However, whether quantum computational…

Quantum Physics · Physics 2025-01-15 Thiago Bergamaschi , Chi-Fang Chen , Yunchao Liu

Estimating quantum partition functions is a critical task in a variety of fields. However, the problem is classically intractable in general due to the exponential scaling of the Hamiltonian dimension $N$ in the number of particles. This…

Quantum Physics · Physics 2024-11-28 Thais de Lima Silva , Lucas Borges , Leandro Aolita

We give a quantum speedup for solving the canonical semidefinite programming relaxation for binary quadratic optimization. This class of relaxations for combinatorial optimization has so far eluded quantum speedups. Our methods combine…

Data Structures and Algorithms · Computer Science 2022-01-26 Fernando G. S L. Brandão , Richard Kueng , Daniel Stilck França

Preparing thermal and ground states is an essential quantum algorithmic task for quantum simulation. In this work, we construct the first efficiently implementable and exactly detailed-balanced Lindbladian for Gibbs states of arbitrary…

Quantum Physics · Physics 2025-10-15 Chi-Fang Chen , Michael J. Kastoryano , András Gilyén

The Gibbs partition function is an important quantity in describing statistical properties of a system in thermodynamic equilibrium. There are several proposals to calculate the partition functions on near-team quantum computers. However,…

Long-range quantum systems, in which the interactions decay as $1/r^{\alpha}$, are of increasing interest due to the variety of experimental set-ups in which they naturally appear. Motivated by this, we study fundamental properties of…

Quantum Physics · Physics 2026-01-08 Jorge Sánchez-Segovia , Jan T. Schneider , Álvaro M. Alhambra

We study the complexity of estimating the partition function $\mathsf{Z}(\beta)=\sum_{x\in\chi} e^{-\beta H(x)}$ for a Gibbs distribution characterized by the Hamiltonian $H(x)$. We provide a simple and natural lower bound for quantum…

Quantum Physics · Physics 2024-04-10 Zherui Chen , Giacomo Nannicini

We establish a systematic framework of unbiased quantum sampling and estimation protocols for the classical Gibbs expectation. This framework generalizes existing approaches to the partition function estimation and has broader applications…

Quantum Physics · Physics 2026-04-02 Xinmiao Li , Jin-Peng Liu

The development of novel quantum many-body computational algorithms relies on robust benchmarking. However, generating such benchmarks is often hindered by the massive computational resources required for exact diagonalization or quantum…

Strongly Correlated Electrons · Physics 2025-12-29 Wei-Bo He , Yun-Tong Yang , Hong-Gang Luo

Semidefinite programs (SDPs) are a particular class of convex optimization problems with applications in combinatorial optimization, operational research, and quantum information science. Seminal work by Brand\~{a}o and Svore shows that a…

Quantum Physics · Physics 2023-10-13 Oscar Watts , Yuta Kikuchi , Luuk Coopmans

Estimating vibrational entropy is a significant challenge in thermodynamics and statistical mechanics due to its reliance on quantum mechanical properties. This paper introduces a quantum algorithm designed to estimate vibrational entropy…

Quantum Physics · Physics 2025-11-25 Shangjie Guo , Corneliu Buda , Nathan Wiebe

We present an algorithm to approximate partition functions of 3-body classical Ising models on two-dimensional lattices of arbitrary genus, in the real-temperature regime. Even though our algorithm is purely classical, it is designed by…

Quantum Physics · Physics 2014-02-05 M. Van den Nest , W. Dür

Algorithms for computing the classical Gaussian quadrature rules (Gauss--Jacobi, Gauss--Laguerre, and Gauss--Hermite) are presented, based on globally convergent fourth-order iterative methods combined with asymptotic approximations, which…

Numerical Analysis · Mathematics 2025-12-15 A. Gil , J. Segura , N. M. Temme

Preparing ground states and thermal states is essential for simulating quantum systems on quantum computers. Despite the hope for practical quantum advantage in quantum simulation, popular state preparation approaches have been challenged.…

Preparing the thermal density matrix $\rho_{\beta} \propto e^{-\beta H}$ corresponding to a given Hamiltonian $H$ is a task of central interest across quantum many-body physics, and is particularly salient when attempting to study it with…

Quantum Physics · Physics 2026-01-14 Dominik Hahn , S. A. Parameswaran , Benedikt Placke

We discuss quantum algorithms that calculate numerical integrals and descriptive statistics of stochastic processes. With either of two distinct approaches, one obtains an exponential speed increase in comparison to the fastest known…

Quantum Physics · Physics 2007-05-23 Daniel S. Abrams , Colin P. Williams