Ground state energy of the Bose--Hubbard model with large coordination number with a polaron-type quantum de Finetti theorem

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Farhat, Shahnaz, Périce, Denis, Petrat, Sören
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917373235167232
author Farhat, Shahnaz
Périce, Denis
Petrat, Sören
author_facet Farhat, Shahnaz
Périce, Denis
Petrat, Sören
contents We consider the ground state energy of the Bose--Hubbard model on a graph with large and homogeneous coordination number. In the limit of infinite coordination number, we prove convergence of the ground state energy to the minimizer of a mean-field energy functional. This functional is obtained by averaging the hopping term over the large number of connected sites, while the interaction energy is not averaged. Hence, the resulting mean-field description is in the strong coupling regime, and is expected to provide a qualitatively correct picture of the phase diagram of the Bose--Hubbard model for large enough coordination number. For our proof, we develop a new version of a de Finetti-type theorem, which we call the polaron-type quantum de Finetti theorem, and which we expect to be a more broadly useful extension of existing quantum de Finetti results. Our theorem covers the case where the Hilbert space is a tensor product of some Hilbert space with a bosonic Fock space. This theorem is applied to the convergence of the ground state energy of the Bose--Hubbard model after reducing it to a polaron-type model.
format Preprint
id arxiv_https___arxiv_org_abs_2603_29562
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Ground state energy of the Bose--Hubbard model with large coordination number with a polaron-type quantum de Finetti theorem
Farhat, Shahnaz
Périce, Denis
Petrat, Sören
Mathematical Physics
Quantum Gases
We consider the ground state energy of the Bose--Hubbard model on a graph with large and homogeneous coordination number. In the limit of infinite coordination number, we prove convergence of the ground state energy to the minimizer of a mean-field energy functional. This functional is obtained by averaging the hopping term over the large number of connected sites, while the interaction energy is not averaged. Hence, the resulting mean-field description is in the strong coupling regime, and is expected to provide a qualitatively correct picture of the phase diagram of the Bose--Hubbard model for large enough coordination number. For our proof, we develop a new version of a de Finetti-type theorem, which we call the polaron-type quantum de Finetti theorem, and which we expect to be a more broadly useful extension of existing quantum de Finetti results. Our theorem covers the case where the Hilbert space is a tensor product of some Hilbert space with a bosonic Fock space. This theorem is applied to the convergence of the ground state energy of the Bose--Hubbard model after reducing it to a polaron-type model.
title Ground state energy of the Bose--Hubbard model with large coordination number with a polaron-type quantum de Finetti theorem
topic Mathematical Physics
Quantum Gases
url https://arxiv.org/abs/2603.29562