Quantum Hall fractions in rotating Bose-Einstein condensates

TL;DR

This paper investigates quantum Hall phases in rotating Bose-Einstein condensates, identifying specific incompressible states and their excitations through exact diagonalization, revealing the presence of Jain sequences and Pfaffian states.

Contribution

It demonstrates the occurrence of Jain principal sequence and Pfaffian states in rotating BECs using exact diagonalization, linking quantum Hall physics to cold atom systems.

Findings

Identification of Jain sequence states at various filling fractions

Observation of Pfaffian state at filling fraction 1

Composite-fermion scheme describes collective excitations

Abstract

We study the Quantum Hall phases that appear in the dilute limit of rotating Bose-Einstein condensates. By exact diagonalization in a spherical geometry we obtain the ground-state and low-lying excited states of a small number of bosons as a function of the filling fraction nu, ratio of the number of bosons to the number of vortices. We show the occurrence of the Jain principal sequence of incompressible liquids for nu = 1/2, 2/3, 3/4, 4/3, 5/4 as well as the Pfaffian state for nu =1. The collective excitations for the Jain sequence are well described by a composite-fermion scheme.