Chiral surface superconductivity in half-Heusler semimetals

TL;DR

This paper investigates the potential for unconventional chiral surface superconductivity with Majorana modes in half-Heusler semimetals, using DFT and RPA calculations to analyze surface states and electron interactions.

Contribution

It introduces the concept of surface superconductivity in half-Heusler semimetals and demonstrates the emergence of chiral superconducting states with Majorana modes through theoretical modeling.

Findings

Surface states in LuPtBi favor chiral superconductivity.

Majorana edge modes are predicted in the surface superconducting phase.

Time-reversal symmetry breaking occurs before bulk superconductivity.

Abstract

We propose the metallic and weakly dispersive surface states of half-Heusler semimetals as a possible domain for the onset of unconventional surface superconductivity ahead of the bulk transition. Using density functional theory (DFT) calculations and the random phase approximation (RPA), we analyse the surface band structure of LuPtBi and its propensity towards Cooper pair formation induced by screened electron-electron interactions in the presence of strong spin-orbit coupling. Over a wide range of model parameters, we find an energetically favoured chiral superconducting condensate featuring Majorana edge modes, while low-dimensional order parameter fluctuations trigger time-reversal symmetry breaking to precede the superconducting transition.