English
Related papers

Related papers: Cluster expansion for ground states of local Hamil…

200 papers

We provide numerical constructions of one-dimensional hyperuniform many-particle distributions that exhibit unusual clustering and asymptotic local number density fluctuations growing more slowly than the volume of an observation window but…

Statistical Mechanics · Physics 2013-05-29 Chase E. Zachary , Salvatore Torquato

We use complexity theory to rigorously investigate the difficulty of classically simulating evolution under many-body localized (MBL) Hamiltonians. Using the defining feature that MBL systems have a complete set of quasilocal integrals of…

Downfolding coupled cluster (CC) techniques have recently been introduced into quantum chemistry as a tool for the dimensionality reduction of the many-body quantum problem. As opposed to earlier formulations in physics and chemistry based…

Quantum Physics · Physics 2022-03-23 Nicholas P. Bauman , Karol Kowalski

Local unitary invariants allow one to test whether multipartite states are equivalent up to local basis changes. Equivalently, they specify the geometry of the "orbit space" obtained by factoring out local unitary action from the state…

Quantum Physics · Physics 2012-12-27 Graeme Mitchison

The partition function and free energy of a quantum many-body system determine its physical properties in thermal equilibrium. Here we study the computational complexity of approximating these quantities for $n$-qubit local Hamiltonians.…

Quantum Physics · Physics 2023-09-22 Sergey Bravyi , Anirban Chowdhury , David Gosset , Pawel Wocjan

The question whether a given quantum state is a ground or thermal state of a few-body Hamiltonian can be used to characterize the complexity of the state and is important for possible experimental implementations. We provide methods to…

Quantum Physics · Physics 2016-06-30 Felix Huber , Otfried Gühne

We introduce a new type of cluster expansion which generalizes a previous formula of Brydges and Kennedy. The method is especially suited for performing a phase-space multiscale expansion in a just renormalizable theory, and allows the…

High Energy Physics - Theory · Physics 2009-07-09 A. Abdesselam , V. Rivasseau

Recently, several claims have been made that certain fundamental problems of distributed computing, including Leader Election and Distributed Consensus, begin to admit feasible and efficient solutions when the model of distributed…

Quantum Physics · Physics 2009-03-09 Cyril Gavoille , Adrian Kosowski , Marcin Markiewicz

A central result in the study of Quantum Hamiltonian Complexity is that the k-Local hamiltonian problem is QMA-complete. In that problem, we must decide if the lowest eigenvalue of a Hamiltonian is bounded below some value, or above…

Quantum Physics · Physics 2017-09-20 Naïri Usher , Matty J. Hoban , Dan E. Browne

Stabilizer states, which are also known as the Clifford states, have been commonly utilized in quantum information, quantum error correction, and quantum circuit simulation due to their simple mathematical structure. In this work, we apply…

Quantum Physics · Physics 2025-06-26 Jiace Sun , Lixue Cheng , Shi-Xin Zhang

Entanglement in the ground state of a many-body quantum system may arise when the local terms in the system Hamiltonian fail to commute with the interaction terms in the Hamiltonian. We quantify this phenomenon, demonstrating an analogy…

Quantum Physics · Physics 2009-11-10 Christopher M. Dawson , Michael A. Nielsen

We briefly summarize properties of quantum Hall states with a pairing or clustering property. Their study employs a fundamental connection with parafermionic Conformal Field Theories. We report on closed form expressions for the many-body…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 K. Schoutens , E. Ardonne , F. J. M. van Lankvelt

We consider a system of classical particles confined in a box $\Lambda\subset\mathbb{R}^d$ with zero boundary conditions interacting via a stable and regular pair potential. Based on the validity of the cluster expansion for the canonical…

Probability · Mathematics 2021-03-30 Giuseppe Scola

An approach is developed, combining the ideas of quantum statistical mechanics and multichannel theory of scattering, for treating statistical systems whose constituents can possess different bound states realized as compact clusters. The…

Statistical Mechanics · Physics 2015-06-25 V. I. Yukalov , E. P. Yukalova

On large-scales, comparable to the horizon, the observable clustering properties of galaxies are affected by various general relativistic effects. To calculate these effects one needs to consistently solve for the metric, densities and…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-21 Nora Elisa Chisari , Matias Zaldarriaga

The formation of galaxy clusters in hierarchically clustering universes is investigated by means of high resolution N-body simulations. The simulations are performed using a newly developed multi-mass scheme which combines a PM code with a…

Astrophysics · Physics 2007-05-23 A. Huss , B. Jain , M. Steinmetz

A theory of structure is formulated for systems of many structureless classical particles with stable local interactions in Euclidean space. Such systems are shown to have their structure in thermodynamic equilibrium determined exactly by a…

Statistical Mechanics · Physics 2026-02-12 John Çamkıran , Fabian Parsch , Glenn D. Hibbard

Starting from the observation that one of the most successful methods for solving the Kohn-Sham equations for periodic systems -- the plane-wave method -- is a spectral method based on eigenfunction expansion, we formulate a spectral method…

Computational Physics · Physics 2016-03-08 Amartya S. Banerjee , Ryan S. Elliott , Richard D. James

Multipartite quantum states saturating the Heisenberg limit of sensitivity typically require full-body correlators to be prepared. On the other hand, experimentally practical Hamiltonians often involve few-body correlators only. Here, we…

Quantum Physics · Physics 2025-12-03 Majid Hassani , Mengyao Hu , Guillem Müller-Rigat , Matteo Fadel , Jordi Tura

The search for highly coherent degrees of freedom in noisy solid-state environments is a major challenge in condensed matter. In disordered dipolar systems, such as magnetically doped insulators, compact clusters of two-level systems (TLS)…

Quantum Physics · Physics 2024-12-10 Lorenzo Amato , Manuel Grimm , Markus Müller