Majorana edge-modes in a spinful particle conserving model

TL;DR

This paper demonstrates the existence and robustness of Majorana edge modes in an interacting, spinful fermionic ladder with conserved particle number, under specific hopping and magnetic field conditions.

Contribution

It introduces a spinful, particle-conserving model with pair hopping that hosts Majorana edge modes, showing their stability against interactions and hopping imbalances.

Findings

Majorana edge modes exist in the model.

Topological phase persists with finite interactions.

Attractive interactions enhance edge mode stability.

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 seems to be more stable in the case when the on-site interaction is an attraction.