Superconductivity in the topological semimetal YPtBi

TL;DR

This paper reports on the discovery of superconductivity in the topologically nontrivial semimetal YPtBi, highlighting its unconventional properties and potential for topological superconductivity research.

Contribution

It provides experimental evidence of superconductivity in YPtBi and explores its topological and surface state characteristics, a novel combination in this material.

Findings

Superconductivity observed below 0.77 K in YPtBi.

Supports the topologically nontrivial semimetal nature of YPtBi.

Indications of surface state contributions to magnetoresistance.

Abstract

The noncentrosymmetric Half Heusler compound YPtBi exhibits superconductivity below a critical temperature T_c = 0.77 K with a zero-temperature upper critical field H_c2(0) = 1.5 T. Magnetoresistance and Hall measurements support theoretical predictions that this material is a topologically nontrivial semimetal having a surprisingly low positive charge carrier density of 2 x 10^18 cm^-3. Unconventional linear magnetoresistance and beating in Shubnikov-de Haas oscillations point to spin-orbit split Fermi surfaces. The sensitivity of magnetoresistance to surface roughness suggests a possible contribution from surface states. The combination of noncentrosymmetry and strong spin-orbit coupling in YPtBi presents a promising platform for the investigation of topological superconductivity.