Phase diagrams of Majorana-Hubbard ladders

Models of interacting Majorana modes may be realized in vortex lattices in superconducting films in contact with topological insulators and may be tuned to the strong-interaction regime by adjusting the chemical potential. Extending the results on one- and two-dimensional Majorana-Hubbard models, here we determine the phase diagrams of two- and four-leg ladders using both field theory and the density-matrix renormalization group (DMRG) methods.