We study a tight-binding model of interacting Majorana (Hermitian) modes on a square lattice. The model may have an experimental realization in a superconducting-film--topological-insulator heterostructure in a magnetic field. We find a rich phase diagram, as a function of interaction strength, including a superfluid phase with spontaneous breaking of an emergent U(1) symmetry, separated by a supersymmetric transition from a gapless normal phase.
@article{arxiv.1706.05469,
title = {Majorana-Hubbard model on the square lattice},
author = {Ian Affleck and Armin Rahmani and Dmitry Pikulin},
journal= {arXiv preprint arXiv:1706.05469},
year = {2017}
}