Fragility of the Laughlin state in an anharmonically-trapped Bose-Einstein condensate

TL;DR

This paper investigates how a slight anharmonicity in the trapping potential of a rotating Bose-Einstein condensate destabilizes the Laughlin state, suggesting experimental realization is highly unlikely for large atom numbers.

Contribution

It introduces a weak quartic potential to model realistic traps and demonstrates the fragility of the Laughlin state under such conditions.

Findings

Laughlin state is highly sensitive to anharmonic perturbations

Achieving Laughlin states experimentally is practically impossible for large atom numbers

Anharmonicity destroys the many-body correlations of the Laughlin state

Abstract

When a Bose-Einstein condensate rotates in a purely harmonic potential with an angular frequency which is close to the trap frequency, its many-body state becomes highly correlated, with the most well-known being the bosonic Laughlin state. To take into account that in a real experiment no trapping potential is ever exactly harmonic, we introduce an additional weak, quartic potential and demonstrate that the Laughlin state is highly sensitive to this extra potential. Our results imply that achieving these states experimentally is essentially impossible, at least for a macroscopic atom number.