Quasihole dynamics as a detection tool for quantum Hall phases

TL;DR

This paper investigates quasihole dynamics in ultracold bosonic gases under synthetic gauge fields, proposing quasihole behavior as a spectroscopic method to identify quantum Hall phases, especially the Laughlin state.

Contribution

It introduces a novel approach to detect quantum Hall phases by analyzing quasihole dynamics and revivals in finite atomic systems.

Findings

Quasiholes in the Laughlin state rotate coherently, conserving angular momentum.

In higher density regimes, quasiholes decay instead of rotating coherently.

Revival periods of quasiholes serve as a spectroscopic signature of strongly correlated phases.

Abstract

Existing techniques for synthesizing gauge fields are able to bring a two-dimensional cloud of harmonically trapped bosonic atoms into a regime where the occupied single-particle states are restricted to the lowest Landau level (LLL). Repulsive short-range interactions drive various transitions from fully condensed into strongly correlated states. In these different phases we study the response of the system to quasihole excitations induced by a laser beam. We find that in the Laughlin state the quasihole performs a coherent constant rotation around the center, ensuring conservation of angular momentum. This is distinct to any other regime with higher density, where the quasihole is found to decay. At a characteristic time, the decay process is reversed, and revivals of the quasihole can be observed in the density. Measuring the period and position of the revival can be used as a spectroscopic tool to identify the strongly correlated phases in systems with a finite number of atoms.