Superconductivity in non-centrosymmetric YPtBi under pressure

TL;DR

This study investigates how applying pressure affects the superconducting properties of non-centrosymmetric YPtBi, revealing enhanced superconductivity and evidence for unconventional pairing mechanisms involving odd-parity components.

Contribution

It provides the first high-pressure single-crystal measurements of YPtBi, demonstrating pressure-induced enhancement of superconductivity and suggesting unconventional pairing due to non-centrosymmetry.

Findings

Superconductivity in YPtBi is enhanced under pressure.

Upper critical field data suggest odd-parity pairing.

Superconducting properties exceed spin-singlet model predictions.

Abstract

We report a high-pressure single-crystal study of the non-centrosymmetric superconductor YPtBi ($T_c = 0.77$ K). Magnetotransport measurements show a weak metallic behavior with a carrier concentration $n \simeq 2.2 \times 10^{19}$ cm$^{-3}$. Resistivity measurements up to $p = 2.51$ GPa reveal superconductivity is promoted by pressure. The reduced upper critical field $B_{c2}(T)$ curves collapse onto a single curve, with values that exceed the model values for spin-singlet superconductivity. The $B_{c2}$ data point to an odd-parity component in the superconducting order parameter, in accordance with predictions for non-centrosymmetric superconductors.