Time-reversal symmetry breaking in the noncentrosymmetric <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>Zr</mml:mi></mml:mrow><mml:mn>3</mml:mn></mml:msub><mml:mi>Ir</mml:mi></mml:math> superconductor
Tian Shang, S. K. Ghosh, Jianzhou Zhao, L. J. Chang, C. Baines, M. K. Lee, Dariusz Jakub Gawryluk, M. Shi, M. Medarde, Jorge Quintanilla, T. Shiroka
Abstract
The Zr${}_{3}$Ir superconductor exhibits the coexistence of two exotic, and normally distinct, features: mixed singlet-triplet pairing and broken time-reversal symmetry. Mixed singlet-triplet pairing can take place in superconductors whose crystal lattices lack inversion symmetry. This relativistic effect, which does not require the breaking of additional symmetries, nor an unconventional pairing mechanism, is often quite small. Broken time-reversal symmetry, on the other hand, means that the superconducting state is magnetic and necessitates an unconventional pairing mechanism. The coexistence of these two phenomena makes Zr${}_{3}$Ir a very unusual material, opening up new perspectives for their understanding.