Wilson Fermions and Axion Electrodynamics in Optical Lattices

TL;DR

This paper proposes a novel scheme using ultracold atoms in optical lattices to realize Wilson fermions, enabling quantum simulation of fermionic gauge theories and exploration of topological phases and axion electrodynamics.

Contribution

It introduces a controllable method to implement Wilson fermions with laser-assisted tunneling in optical lattices, advancing quantum simulation capabilities.

Findings

First controllable realization of Wilson fermions with ultracold atoms

Potential to explore 3D topological insulators and axion electrodynamics

Enables testing of fundamental physics predictions in a laboratory setting

Abstract

The formulation of massless relativistic fermions in lattice gauge theories is hampered by the fundamental problem of species doubling, namely, the rise of spurious fermions modifying the underlying physics. A suitable tailoring of the fermion masses prevents such abundance of species, and leads to the so-called Wilson fermions. Here we show that ultracold atoms provide us with the first controllable realization of these paradigmatic fermions, thus generating a quantum simulator of fermionic lattice gauge theories. We describe a novel scheme that exploits laser-assisted tunneling in a cubic optical superlattice to design the Wilson fermion masses. The high versatility of this proposal allows us to explore a variety of interesting phases in three-dimensional topological insulators, and to test the remarkable predictions of axion electrodynamics.