Momentum-space Aharonov-Bohm interferometry in Rashba spin-orbit coupled Bose-Einstein condensates

TL;DR

This paper proposes a scheme for momentum-space Aharonov-Bohm interferometry in Rashba spin-orbit coupled Bose-Einstein condensates to measure Berry phases, aiding the characterization of topological properties in ultracold atomic systems.

Contribution

It introduces a novel interferometry method using Zeeman field changes to directly detect Berry phases in Rashba systems, supported by a variational model and simulations.

Findings

Berry phase with a Dirac point revealed by dark interference fringes

Fringe contrast varies with external Zeeman field

Agreement between semiclassical trajectories and Gross-Pitaevskii simulations

Abstract

Since the recent experimental realization of synthetic Rashba spin-orbit coupling paved a new avenue for exploring and engineering topological phases in ultracold atoms, a precise, solid detection of Berry phase has been desired for unequivocal characterization of system topology. Here, we propose a scheme to conduct momentum-space Aharonov-Bohm interferometry in a Rashba spin-orbit coupled Bose-Einstein condensate with a sudden change of in-plane Zeeman field, capable of measuring the Berry phase of Rashba energy bands. We find that the Berry phase with the presence of a Dirac point is directly revealed by a robust dark interference fringe, and that as a function of external Zeeman field is characterized by the contrast of fringes. We also build a variational model describing the interference process with semiclassical equations of motion of essential dynamical quantities, which lead to agreeable trajectories and geometric phases with the real-time simulation of Gross-Pitaevskii equation. Our study would provide timely guidance for the experimental detection of Berry phase in ultracold atomic systems and help further investigation on their interference dynamics in momentum space.