Single-gap two-band superconductivity well above the Pauli limit in non-centrosymmetric TaIr$_2$B$_2$

J. Kacmarcik; Z. Pribulova; T. Shiroka; F. Kosuth; P. Szabo; M. J. Winiarski; S. Krolak; J. Jaroszynski; T. Shang; R. J. Cava; C. Marcenat; T. Klein; T. Klimczuk; P. Samuely

doi:10.1016/j.supcon.2025.100167

paper

Single-gap two-band superconductivity well above the Pauli limit in non-centrosymmetric TaIr $_{2}$ B $_{2}$

arXiv:2504.00662 · doi:10.1016/j.supcon.2025.100167

Abstract

Non-centrosymmetric superconducting materials represent an exciting class of novel superconductors featuring a variety of unconventional properties, including mixed-parity pairing and very high upper critical fields. Here, we present a comprehensive study of TaIr $_{2}$ B $_{2}$ (with $T_{c}$ = 5.1 K), using a set of complementary experimental methods, including bulk- and surface-sensitive techniques. We provide evidence that this system is a two-band, yet it behaves as a single-gap superconductor with a strong coupling. The upper critical field of TaIr $_{2}$ B $_{2}$ significantly exceeds the Pauli limit and exhibits a nearly linear temperature dependence down to the lowest temperatures. This behavior, rarely seen in superconductors, is discussed in terms of anti-symmetric spin-orbit interaction, two-band-, and strong-coupling effects, as well as disorder.

10 pages, 8 figures, suppl. material

Single-gap two-band superconductivity well above the Pauli limit in non-centrosymmetric TaIr2​B2​

Abstract

Single-gap two-band superconductivity well above the Pauli limit in non-centrosymmetric TaIr $_{2}$ B $_{2}$