Nontrivially Topological Phase Structure of Ideal Bose Gas System within Different Boundary Conditions

TL;DR

This paper investigates the topological phase structure of an ideal Bose gas under different boundary conditions, revealing nontrivial topological ground states that are distinguishable by particle susceptibility, with implications for QCD and statistical models.

Contribution

It demonstrates that ideal Bose gases exhibit topologically nontrivial ground states under various boundary conditions, a novel insight beyond traditional symmetry breaking theories.

Findings

Ground states are topologically nontrivial under both boundary conditions.

Different boundary conditions lead to distinct topological phases.

The topological nature can be identified via off-diagonal particle number susceptibility.

Abstract

The phase structure of ideal Bose gas system within different boundary conditions, i.e., the periodic boundary condition and Dirichlet boundary condition in this work, in an infinite volume, is investigated. It is found that the ground states of ideal Bose gas within those two boundary conditions are both topologically nontrivial, which can not be classified by the traditional symmetry breaking theory. The ground states are different topological phases corresponding to those two boundary conditions, which can be distinguished by the off--diagonal particle number susceptibility. Moreover, this result is universal. The boundary condition may play an important role in pining the critical endpoint of QCD diagram on the approach of the lattice simulations and the computation of some solvable statistical models .