Superconducting properties and gap structure of the topological superconductor candidate Ti_(3)Sb

Abstract

We present a study of the superconducting properties of the candidate topological superconductor Ti_(3)Sb. Electrical transport measurements show zero resistance with a T_(c,onset) of ~ 5.9 K with a transition width ΔT_c~ 0.6 K. The superconducting phase boundaries as derived from magneto-transport and magnetic susceptibility measurements agree well. We estimate an upper critical field Bc2(0)~4.5 T. A Ginzburg-Landau (GL) analysis yields values of the coherence length and penetration depth of ζ = 6.2 nm and λ = 340 nm, respectively, and a GL parameter ~ 55, indicating extreme type-II behavior. Furthermore, we observed a step height in the specific heat (ΔC_e)/(γT_c )~1.61, a value larger than the Bardeen-Cooper-Schrieffer (BCS) value of 1.43, suggesting modest coupling. Measurements of the temperature dependence of the London penetration depth via the tunnel-diode oscillator (TDO) technique down to ~ 450 mK show a full superconducting gap, consistent with a conventional s-wave gap structure.

19 pages, 6 figures

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Cited by in corpus (4)

• Dirac surface states, multiorbital dimerization and superconductivity in Nb- and Ta-based A15 compounds
• Fermi Surface Topology and Magneto-transport Properties of Superconducting Pd${}_3$Bi${}_2$Se${}_2$
• Determination of the London penetration depth with the tunnel diode oscillator technique
• A15 Phase Ta3Sb Thin Films: Direct Synthesis, Charge Transport and Spin-Orbit Torque