Transport signatures of Floquet Majorana modes in Josephson junctions

We theoretically study the transport signature of unpaired Floquet Majorana edge modes in the Josephson current in weakly linked, periodically driven topological superconductors. In certain cases, similar to the case for static unpaired Majorana edge modes, we find that the Josephson current involving Floquet Majorana modes also shows a $4\pi$-periodic nature. At this limit, the current is also linearly dependent on the coupling between superconductors. We match our numerical results using Floquet Green’s function technique with analytical expressions for the current, the occupation of the Floquet bands, and a perturbative analysis of the quasienergies.