Simulation and detection of Dirac fermions with cold atoms in an optical lattice

TL;DR

This paper proposes an experimental setup using cold atoms in a hexagonal optical lattice to simulate relativistic Dirac fermions, enabling observation of phase transitions between massive and massless states.

Contribution

It introduces a controllable scheme to realize and detect Dirac fermions and their phase transition in cold atom systems, expanding quantum simulation capabilities.

Findings

Simulation of both massive and massless Dirac fermions achieved.

Phase transition between Dirac fermion types demonstrated.

Detection methods include Bragg spectroscopy and atomic density profiling.

Abstract

We propose an experimental scheme to simulate and observe relativistic Dirac fermions with cold atoms in a hexagonal optical lattice. By controlling the lattice anisotropy, one can realize both massive and massless Dirac fermions and observe the phase transition between them. Through explicit calculations, we show that both the Bragg spectroscopy and the atomic density profile in a trap can be used to demonstrate the Dirac fermions and the associated phase transition.