Quantum phases of quadrupolar Fermi gases in optical lattices

TL;DR

This paper proposes using quadrupolar Fermi gases in optical lattices to simulate complex many-body quantum phases, revealing a rich phase diagram with potential for topological superfluid creation.

Contribution

It introduces a novel platform utilizing quadrupolar atoms in optical lattices, expanding quantum simulation capabilities for many-body systems.

Findings

Rich phase diagram with unconventional BCS and charge density wave phases

Potential to realize topological superfluid states

Feasibility with stable quadrupolar atomic species

Abstract

We introduce a new platform for quantum simulation of many-body systems based on nonspherical atoms or molecules with zero dipole moment but possessing a significant value of electric quadrupole moment. We consider a quadrupolar Fermi gas trapped in a 2D square optical lattice, and show that the peculiar symmetry and broad tunability of the quadrupole-quadrupole interaction results in a rich phase diagram encompassing unconventional BCS and charge density wave phases, and opens up a perspective to create topological superfluid. Quadrupolar species, such as metastable alkaline-earth atoms and homonuclear molecules, are stable against chemical reactions and collapse and are readily available in experiment at high densities.