Majorana edge modes in a spinful-particle conserving model

Abstract

We show the presence of Majorana edge modes in an interacting fermionic ladder with spin in a number-conserved setting. The interchain single-particle hopping is suppressed and only a pair hopping is present between the different chains of the ladder. Additionally, the hopping along the chains is spin imbalanced and a transverse magnetic field is applied breaking time-reversal invariance. We study the robustness of the topological phase with respect to an on-site interaction between the spin-up and spin-down fermions and the spin-dependent imbalance of the hopping. The main result of the present work is that the topological phase survives for a finite region in the parameter space in the presence of interactions. The localized Majorana edge modes seem to be more stable in the case when the on-site interaction is an attraction.