Manifestation of the Berry connection in chiral lattice systems

TL;DR

This paper demonstrates how the Berry connection influences electron dynamics in chiral lattice systems, revealing a measurable effect akin to the Aharonov-Bohm phenomenon, supported by photonic experiments with topological quantum walks.

Contribution

It introduces a novel observable effect of the Berry connection on chiral displacement in lattice systems, confirmed through experimental realization.

Findings

Berry connection affects mean chiral displacement

Photonic topological quantum walk demonstrates the effect

Establishes a gauge field influence in solid-state systems

Abstract

The Aharonov-Bohm effect is a physical phenomenon where the vector potential induces a phase shift of electron wavepackets in regions with zero magnetic fields. It is often referred to as evidence for the physical reality of the vector potential. A similar effect can be observed in solid-state systems, where the Berry connection can influence electron dynamics. Here, we show that in chiral-symmetric processes the Berry connection determines an observable effect on the mean chiral displacement of delocalized wavefunctions. This finding is supported by a photonic experiment realizing a topological quantum walk, and demonstrates a new effect that can be attributed directly to the presence of a gauge field.