Fractionally quantized Berry's phase in an anisotropic magnet on the Kagome lattice

TL;DR

This paper numerically investigates a fractionally quantized Berry phase in an anisotropic spin-1/2 XXZ model on the Kagome lattice, revealing a non-zero fractional Berry phase associated with a tripartite entangled plaquette phase.

Contribution

It demonstrates the fractional quantization of Berry phase in an anisotropic Kagome lattice model, linking it to a specific entangled phase not previously characterized by this measure.

Findings

Berry phase becomes fractionally quantized with increased anisotropy

Fractional Berry phase correlates with tripartite entangled plaquette phase

Numerical evidence supports the phase transition associated with Berry phase change

Abstract

A fractionally quantized Berry phase is examined numerically in an anisotropic spin-1/2 XXZ model on the Kagome lattice. It is shown that the Berry phase has a fractionally quantized and non-zero value when an anisotropy is increased, which is consistent with the emergence of the tripartite entangled plaquette phase discussed by J. Carrasquilla et al. [Phys. Rev. B96, 054405 (2017)].