Effect of strong intersite Coulomb interaction on the topological properties of a superconducting nanowire

TL;DR

This paper investigates how strong intersite Coulomb interactions affect Majorana excitations in a superconducting nanowire with extended s-wave pairing, revealing the persistence of topological phases under certain conditions.

Contribution

It demonstrates the impact of intersite Coulomb repulsion on the topological properties and Majorana states in superconducting nanowires using density matrix renormalization group simulations.

Findings

Emergence of two subbands in the lower Hubbard band with increased electron repulsion.

Topologically nontrivial phase with edge states persists at minimal electron or hole concentration.

Strong intersite Coulomb interaction influences the topological phase stability.

Abstract

For superconducting nanowire with the pairing of extended s-type symmetry, Rashba spin-orbit interaction in a magnetic field, the influence of strong intersite charge correlations on single-particle Majorana excitations is analyzed. This problem is investigated on the basis of the density matrix renormalization group numerical method. It is shown that with an increase in the repulsion intensity of electrons located at the neighboring sites, two subbands emerge in the lower Hubbard band of the open system. Based on calculations of the Majorana polarization and degeneracy of the entanglement spectrum, it was found that a topologically nontrivial phase with one edge state survives at the edge of each of the subbands where the concentration of electrons or holes is minimal.