English
Related papers

Related papers: Random Phase Product Sate for Canonical Ensemble

200 papers

We consider a quantum system consisting of a regular chain of elementary subsystems with nearest neighbor interactions and assume that the total system is in a canonical state with temperature $T$. We analyze under what condition the state…

Quantum Physics · Physics 2009-11-10 M. Hartmann , G. Mahler , O. Hess

With the path integral approach, the thermal average in a multi-electronic-state quantum systems can be approximated by the ring polymer representation on an extended configuration space, where the additional degrees of freedom are…

Numerical Analysis · Mathematics 2020-11-24 Xiaoyu Lei , Zhennan Zhou

We use an extension of the diagrammatic rules in random matrix theory to evaluate spectral properties of finite and infinite products of large complex matrices and large hermitian matrices. The infinite product case allows us to define a…

Mathematical Physics · Physics 2015-06-26 Ewa Gudowska-Nowak , Romuald A. Janik , Jerzy Jurkiewicz , Maciej A. Nowak

Motivated by applications to 3D printing, this paper presents two algorithms for calculating an ensemble of solutions to heat conduction problems. The ensemble average is the most likely temperature distribution and its variance gives an…

Numerical Analysis · Mathematics 2017-08-04 Joseph A. Fiordilino

We study a random code ensemble with a hierarchical structure, which is closely related to the generalized random energy model with discrete energy values. Based on this correspondence, we analyze the hierarchical random code ensemble by…

Disordered Systems and Neural Networks · Physics 2011-02-08 Tomoyuki Obuchi , Kazutaka Takahashi , Koujin Takeda

The equivalence of thermodynamic ensembles is at the heart of statistical mechanics and central to our understanding of equilibrium states of matter. Recently, it has been shown that there is a formal connection between the dynamics of open…

Quantum Physics · Physics 2015-07-29 Jukka Kiukas , Madalin Guta , Igor Lesanovsky , Juan P. Garrahan

It is a long-standing challenge to accurately and efficiently compute thermodynamic quantities of many-body systems at thermal equilibrium. The conventional methods, e.g., Markov chain Monte Carlo, require many steps to equilibrate. The…

Statistical Mechanics · Physics 2025-12-10 Shuo-Hui Li , Yao-Wen Zhang , Ding Pan

We introduce a functional matrix product state (FMPS) based method for simulating the real-space representation of continuous-variable (CV) quantum computation. This approach efficiently simulates non-Gaussian CV systems by leveraging their…

Quantum Physics · Physics 2026-03-26 Andreas Bock Michelsen , Frederik K. Marqversen , Michael Kastoryano

Using an imaginary-time matrix-product state (MPS) based quantum impurity solver we perform a realistic dynamical mean-field theory (DMFT) calculation combined with density functional theory (DFT) for Sr$_2$RuO$_4$. We take the full…

Strongly Correlated Electrons · Physics 2020-01-22 Nils-Oliver Linden , Manuel Zingl , Claudius Hubig , Olivier Parcollet , Ulrich Schollwöck

Consider a mixed quantum mechanical state, describing a statistical ensemble in terms of an arbitrary density operator $\rho$ of low purity, $\tr\rho^2\ll 1$, and yielding the ensemble averaged expectation value $\tr(\rho A)$ for any…

Statistical Mechanics · Physics 2009-11-13 Peter Reimann

We investigate joint spectral characteristics of a family of matrices $\mathcal F $, associated with products in the semigroup generated by $\mathcal F$. In the literature, extremal measures such as the well-known joint spectral radius and…

Dynamical Systems · Mathematics 2026-04-27 Francesco Paolo Maiale , Anastasiia Trofimova , Nicola Guglielmi

The preparation of quantum Gibbs states at finite temperatures is a cornerstone of quantum computation, enabling applications in quantum simulation of many-body systems, machine learning via quantum Boltzmann machines, and optimization…

Quantum Physics · Physics 2026-04-17 Rui-Hao Li , Semeon Valgushev , Khadijeh Najafi

This paper demonstrates the feasibility of trajectory learning for ensemble forecasts by employing the continuous ranked probability score (CRPS) as a loss function. Using the two-scale Lorenz '96 system as a case study, we develop and…

Numerical Analysis · Mathematics 2025-10-23 Sagy Ephrati , James Woodfield

The Random Batch Method (RBM) proposed in [Jin et al. J Comput Phys, 2020] is an efficient algorithm for simulating interacting particle systems (IPS). In this paper, we investigate the Random Batch Method with replacement (RBM-r), which is…

Numerical Analysis · Mathematics 2025-11-04 Zhenhao Cai , Jian-Guo Liu , Yuliang Wang

We consider the statistical mechanics of a classical particle in a one-dimensional box subjected to a random potential which constitutes a Wiener process on the coordinate axis. The distribution of the free energy and all correlation…

Condensed Matter · Physics 2009-10-28 Kurt Broderix , Reiner Kree

We study various methods to generate ensembles of random density matrices of a fixed size N, obtained by partial trace of pure states on composite systems. Structured ensembles of random pure states, invariant with respect to local unitary…

Quantum Physics · Physics 2019-02-27 Karol Zyczkowski , Karol A. Penson , Ion Nechita , Benoit Collins

In this note, we describe a method for reconstructing matrix product states from a small number of efficiently-implementable measurements. Our method is exponentially faster than standard tomography, and it can also be used to certify that…

Quantum Physics · Physics 2010-02-26 Olivier Landon-Cardinal , Yi-Kai Liu , David Poulin

Three methods to describe collective motion, Random Phase Approximation (RPA), Wigner Function Moments (WFM) and the Green's Function (GF) method are compared in detail and their physical content analyzed on an example of a simple model,…

Nuclear Theory · Physics 2015-06-26 E. B. Balbutsev , P. Schuck

I study the Sine-Gordon (SG) and Sinh-Gordon (ShG) quantum field theories with a recently introduced variational method, the relativistic continuous matrix product states (RCMPS). The main advantage is to work directly in the thermodynamic…

High Energy Physics - Theory · Physics 2022-09-13 Antoine Tilloy

Common wisdom says that the entanglement of fermionic systems can be low in the second quantization formalism but is extremely large in the first quantization. Hence Matrix Product State (MPS) methods based on moderate entanglement have…

Quantum Physics · Physics 2026-03-31 Jheng-Wei Li , Xavier Waintal