High critical temperature nodal superconductors as building block for time-reversal invariant topological superconductivity

TL;DR

This paper explores how high-temperature nodal superconductors can be used to realize time-reversal invariant topological superconductivity, focusing on Majorana bound states in semiconductor wires with strong spin-orbit coupling.

Contribution

It provides a microscopic analysis of the proximity effect from d-wave superconductors on spin-orbit coupled wires, identifying optimal conditions for topological phases.

Findings

Induced superconductivity characterized via numerical and analytical methods

Identification of parameters for nontrivial topological phases

Potential realization of Majorana doublets at wire boundaries

Abstract

We study possible applications of high critical temperature nodal superconductors for the search for Majorana bound states in the DIII class. We propose a microscopic analysis of the proximity effect induced by d-wave superconductors on a semiconductor wire with strong spin-orbit coupling. We characterize the induced superconductivity on the wire employing a numerical self-consistent tight-binding Bogoliubov-de Gennes approach, and analytical considerations on the Green's function. The order parameter induced on the wire, the pair correlation function, and the renormalization of the Fermi points are analyzed in detail, as well as the topological phase diagram in the case of weak coupling. We highlight optimal Hamiltonian parameters to access the nontrivial topological phase which could display time-reversal invariant Majorana doublets at the boundaries of the wire.