Superconductivity in half-Heusler compound TbPdBi

TL;DR

This study investigates the coexistence of superconductivity and antiferromagnetism in the half-Heusler compound TbPdBi, revealing unconventional superconducting behavior and potential topological properties.

Contribution

It reports the first observation of superconductivity coexisting with antiferromagnetism in TbPdBi, highlighting its unconventional superconducting characteristics and topological features.

Findings

Superconductivity at 1.7 K coexists with antiferromagnetism at 5.5 K.

Unusual linear temperature dependence of the upper critical field $H_{c2}$.

Resistivity plateau when superconductivity is suppressed, indicating topological behavior.

Abstract

We have studied the half-Heusler compound TbPdBi through resistivity, magnetization, Hall effect and heat capacity measurements. A semimetal behavior is observed in its normal state transport properties, which is characterized by a large negative magnetoresistance below 100 K. Notably, we find the coexistence of superconductivity and antiferromagnetism in this compound. The superconducting transition appears at 1.7 K, while the antiferromagnetic phase transition takes place at 5.5 K. The upper critical field $H_{c2}$ shows an unusual linear temperature dependence, implying unconventional superconductivity. Moreover, when the superconductivity is suppressed by magnetic field, its resistivity shows plateau behavior, a signature often seen in topological insulators/semimetals. These findings establish TbPdBi as a platform for study of the interplay between superconductivity, magnetism and non-trivial band topology.