NbIr${}_2$B${}_2$ and TaIr${}_2$B${}_2$ -- new low symmetry noncentrosymmetric superconductors with strong spin orbit coupling

Abstract

Superconductivity was first observed more than a century ago, but the search for new superconducting materials remains a challenge. The Cooper pairs in superconductors are ideal embodiments of quantum entanglement. Thus, novel superconductors can be critical for both learning about electronic systems in condensed matter and for possible application in future quantum technologies. Here two previously unreported materials, NbIr${}_2$B${}_2$ and TaIr${}_2$B${}_2$, are presented with superconducting transitions at 7.2 and 5.2 K, respectively. They display a unique noncentrosymmetric crystal structure, and for both compounds the magnetic field that destroys the superconductivity at 0 K exceeds one of the fundamental characteristics of conventional superconductors (the Pauli limit), suggesting that the superconductivity may be unconventional. Supporting this experimentally based deduction, first-principle calculations show a spin split Fermi surface due to the presence of strong spin-orbit coupling. These materials may thus provide an excellent platform for the study of non-BCS superconductivity in intermetallic compounds.

36 pages, 11 figures

References in corpus (4)

• Extremely strong-coupling superconductivity and anomalous lattice properties in the beta-pyrochlore oxide KOs2O6
• Pressure effects on the unconventional superconductivity of the noncentrosymmetric LaNiC2
• Electronic and lattice properties of non-centrosymmetric superconductors ThTSi (T = Co, Ir, Ni, and Pt)
• Investigations of the superconducting ground state of Zr${}_3$Ir: Introducing a new noncentrosymmetric superconductor

Cited by in corpus (12)

• Role of surface functional groups to superconductivity in Nb${}_2$C-MXene: Experiments and density functional theory calculations
• Group-9 Transition Metal Suboxides Adopting the Filled-Ti${}_2$Ni Structure: A Class of Superconductors Exhibiting Exceptionally High Upper Critical Fields
• Electronic structure, electron-phonon coupling and superconductivity in noncentrosymmetric ThCoC2 from ab initio calculations
• Topological properties of non-centrosymmetric superconductors $T$Ir${}_2$B${}_2$ ($T$=Nb, Ta)
• Anisotropic, multiband, and strong-coupling superconductivity of the Pb0.64Bi0.36 alloy
• Accelerating the Search for Superconductors Using Machine Learning
• Time reversal invariant single gap superconductivity with upper critical field larger than Pauli limit in NbIr${}_2$B${}_2$
• Discovery of the Type-II Superconductor Ta${}_4$Rh${}_2$C${}_{1-\delta }$ with a High Upper Critical Field
• Thermodynamic parameters of atomically thin superconductors derived from the upper critical field
• Quantum oscillations and transport properties of layered single-crystal SrCu${}_4$As${}_2$
• Mo${}_3$ReRuC: A noncentrosymmetric superconductor formed in the MoReRu-Mo${}_2$C system
• Single-gap two-band superconductivity well above the Pauli limit in non-centrosymmetric TaIr${}_2$B${}_2$