Berry's Phases of Ground States of Interacting Spin-One Bosons: Chains of Monopoles and Monosegments

TL;DR

This paper investigates the topological properties of ground states of spin-one bosons under varying magnetic fields, revealing a chain of monopoles and monosegments that influence Berry's phases and topological charge conservation.

Contribution

It introduces the concept of monosegments replacing monopoles in Berry's connection potentials and analyzes their effects on Berry's phases in spin-one boson systems.

Findings

Berry's connection potentials are determined by monosegments rather than monopoles.

Berry's phases exhibit step functions modulated by magnetic field gradients.

Total topological charge remains conserved in the parameter space.

Abstract

We study Berry's connection potentials of many-body ground states of spin-one bosons with antiferromagnetic interactions in adiabatically varying magnetic fields. We find that Berry's connection potentials are generally determined by, instead of usual singular monopoles, linearly positioned monosegments each of which carries one unit of topological charge; in the absence of a magnetic field gradient this distribution of monosegments becomes a linear chain of monopoles. Consequently, Berry's phases consist of a series of step functions of magnetic fields; a magnetic field gradient causes rounding of these step-functions. We also calculate Berry's connection fields, profiles of monosegments and show that the total topological charge is conserved in a parameter space.