Topological pump and bulk-edge-correspondence in an extended Bose-Hubbard model

TL;DR

This paper explores the topological properties of an extended Bose-Hubbard model with multi-body constraints, revealing various symmetry-protected topological phases, topological pumps, and the bulk-edge correspondence in interacting bosonic systems.

Contribution

It introduces a comprehensive analysis of topological phases and pumps in an extended Bose-Hubbard model, demonstrating the bulk-edge correspondence in an interacting bosonic system.

Findings

Identification of multiple SPT phases using Berry phase and entanglement spectrum

Construction of bosonic topological pumps connecting different SPT phases

Observation of plateau transitions via many-body Chern numbers and edge state contributions

Abstract

An extended Bose-Hubbard model (EBHM) with three- and four-body constraints can be feasible in cold atoms in an optical lattice. A rich phase structure including various symmetry-protected topological (SPT) phases is obtained numerically with suitable parameter settings and particle filling. The SPT phase is characterized by the Berry phase as a local topological order parameter and the structure of the entanglement spectrum (ES). Based on the presence of various topological phases, separated by gapless phase boundaries, the EBHM exhibits various bosonic topological pumps, which are constructed by connecting the different SPT phases without gap closing. The bulk topological pumps exhibit the plateau transitions characterized by many-body Chern numbers. For the system with boundary, the center of mass (CoM) under grand canonical ensemble elucidates the contributions of multiple edge states and reveals the topology of the system. We demonstrate that the interacting bosonic pumps obey the bulk-edge-correspondence.