Mott Insulators of Ultracold Fermionic Alkaline Earth Atoms: Underconstrained Magnetism and Chiral Spin Liquid

TL;DR

This paper explores Mott insulators of ultracold fermionic alkaline earth atoms, revealing a chiral spin liquid state with topological order and fractional statistics, contrasting traditional SU(2) magnetism.

Contribution

It introduces a novel chiral spin liquid phase in SU(N) symmetric Mott insulators, highlighting its topological properties and potential experimental realization.

Findings

Classical ground state is highly degenerate on the square lattice.

Large-N limit yields a chiral spin liquid with topological order.

Potential for realizing non-Abelian anyons with alkaline earth atoms.

Abstract

We study Mott insulators of fermionic alkaline earth atoms, described by Heisenberg spin models with enhanced SU(N) symmetry. In dramatic contrast to SU(2) magnetism, more than two spins are required to form a singlet. On the square lattice, the classical ground state is highly degenerate and magnetic order is thus unlikely. In a large-N limit, we find a chiral spin liquid ground state with topological order and Abelian fractional statistics. We discuss its experimental detection. Chiral spin liquids with non-Abelian anyons may also be realizable with alkaline earth atoms.