Time-Reversal Symmetry Breaking in Re-Based Kagome Lattice Superconductor

TL;DR

This study explores the unconventional superconducting properties of Re$_2$Zr, revealing potential time-reversal symmetry breaking and two-gap behavior, indicating complex order parameters in this newly identified superconductor.

Contribution

It reports the discovery of Re$_2$Zr as a new unconventional superconductor with evidence of time-reversal symmetry breaking and two-gap superconductivity.

Findings

Re$_2$Zr is a moderately coupled two-gap superconductor.

Evidence suggests possible time-reversal symmetry breaking.

Re$_2$Zr is identified as a new unconventional superconductor.

Abstract

We investigated the Re-based kagome superconductor Re$_2$Zr through various measurements, including resistivity, magnetization, specific heat, and muon spin rotation and relaxation spectroscopy. These results suggest that Re$_2$Zr is a moderately coupled potential two-gap superconductor. Zero-field muon relaxation data indicate the possible presence of a time-reversal symmetry-breaking state in the superconducting ground state. Our investigation identifies Re$_{2}$Zr as a new unconventional superconductor with a potential complex order parameter that warrants considerable experimental and theoretical interest.