Simulating Wess-Zumino Supersymmetry Model in Optical Lattices

We study a cold atom-molecule mixture in two-dimensional optical lattices, in which fermionic atoms have a Dirac-type dispersion. We show that by fine-tuning the atomic and molecular interactions, such mixtures can simulate Wess-Zumino supersymmetry (SUSY) model, the first example of SUSY theories. At zero temperature, SUSY is not spontaneously broken for this simplest SUSY model, which implies identical relativistic dispersions of the atom and its superpartner, bosonic diatom molecule. This defining signature of SUSY can be probed by single particle spectroscopies. Thermal breaking of SUSY at finite temperature is accompanied by a thermal Goldstone fermion, i.e., phonino excitation. This and other signatures of broken SUSY can also be probed experimentally.