Meta-nematic, smectic and crystalline phases of dipolar fermions in an optical lattice

TL;DR

This paper proposes a cold atom setup using optical lattices and dipolar interactions to realize and study various liquid crystalline phases, including meta-nematic, smectic, and crystalline states, revealing a complex phase diagram.

Contribution

It introduces a tunable model for soft quantum matter physics with a rich phase diagram of liquid crystalline phases in ultracold dipolar fermions.

Findings

Identification of a meta-nematic transition involving dimensionality change

Discovery of a smectic stripe phase

Observation of a checkerboard crystalline phase

Abstract

It has been suggested that some strongly correlated matter might be understood qualitatively in terms of liquid crystalline phases intervening between the Fermi gas and the Wigner crystal or Mott insulator. We propose a tunable realisation of this soft quantum matter physics in an ultra-cold gas. It uses optical lattices and dipolar interactions to realise a particularly simple model. Our analysis reveals a rich phase diagram featuring a meta-nematic transition where the Fermi liquid changes dimensionality; a smectic phase (stripes); and a crystalline, `checkerboard' phase.