Topological phases of an interacting Majorana Benalcazar-Bernevig-Hughes model

TL;DR

This paper investigates how Coulomb interactions affect a second-order topological superconductor model with Majorana modes, demonstrating the robustness of topological phases under strong interactions using DMRG simulations.

Contribution

It provides the first detailed numerical analysis of the interacting Majorana Benalcazar-Bernevig-Hughes model, showing topological phase stability with strong Coulomb repulsion.

Findings

Topological phases remain robust under strong Coulomb interactions.

Majorana corner modes persist despite interactions.

Entanglement spectrum degeneracy indicates stable topological order.

Abstract

We study the effects of Coulomb repulsive interactions on a Majorana Benalcazar-Bernevig-Hughes (MBBH) model. The MBBH model belongs to the class of second--order topological superconductors ($HOTSC_2$), featuring robust Majorana corner modes. We consider an interacting strip of four chains of length $L$ and perform a DMRG numerical analysis based on a tensor--network approach. Study of the nonlocal fermionic correlations and of the degenerate entanglement spectrum indicates that the topological phases are robust in the presence of interactions, even in the strongly interacting regime.