Strongly Correlated States of Ultracold Rotating Dipolar Fermi Gases

TL;DR

This paper investigates the complex ground and excited states of rotating dipolar Fermi gases, revealing a transition from incompressible liquids to crystalline order as particle number and filling factors change.

Contribution

It introduces a detailed analysis of strongly correlated states in rotating dipolar Fermi gases, highlighting novel composite fermion states and the competition between bulk and edge configurations.

Findings

The Laughlin state at filling 1/3 has a significant energy gap and behaves as an incompressible Fermi liquid.

At lower fillings, the system favors crystalline order over liquid states.

Intermediate regimes show competition between bulk and edge configurations, complicating state descriptions.

Abstract

We study strongly correlated ground and excited states of rotating quasi-2D Fermi gases constituted of a small number of dipole-dipole interacting particles with dipole moments polarized perpendicular to the plane of motion. As the number of atoms grows, the system enters {\it an intermediate regime}, where ground states are subject to a competition between distinct bulk-edge configurations. This effect obscures their description in terms of composite fermions and leads to the appearance of novel composite fermion quasi-hole states. In the presence of dipolar interactions, the principal Laughlin state at filling $\nu=1/3$ exhibits a substantial energy gap for neutral (total angular momentum conserving) excitations, and is well-described as an incompressible Fermi liquid. Instead, at lower fillings, the ground state structure favors crystalline order.