Nodeless superconductivity in quasi-one-dimensionalNb2PdS5: AμSRstudy

Abstract

Muon spin relaxation and rotation (μSR) measurements have been performed to study the superconducting and magnetic properties of Nb 2 PdS 5 . Zero-field μSR data show that no sizable spontaneous magnetization arises with the onset of superconductivity in Nb 2 PdS 5 , which indicates that the time-reversal symmetry is probably preserved in the superconducting state of this system. A strong diamagnetic shift is observed in the transverse-field μSR data practically ruling out a dominant triplet-pairing superconducting state in Nb 2 PdS 5 . The temperature dependence of magnetic penetration depth evidences the existence of a single s-wave energy gap (0) with a gap value of 1.07(4) meV at zero temperature. The ratio (0)/k B T c = 2.02(9) indicates that Nb 2 PdS 5 should be considered as a moderately strong-coupling superconductor. The magnetic penetration depth at zero temperature is 785(20) nm, indicating a very low superfluid density consistent with the quasi-one-dimensional nature of this system.

Single gap s-wave superconductivity in Nb2PdS5

“…The result from this model converges to single gap equation which suggests single gap in this compound. The recent report of SR study on this compound also confirms nodeless s-wave superconductivity[21].ConclusionWe have studied penetration depth measurement in Nb 2 PdS 5 using tunnel diode oscillator technique. The low temperature penetration depth data is best described by BCS svalue of energy gap value Δ 0 ~ 1.05meV.…”

Multigap superconductivity in chiral noncentrosymmetric TaRh2B2

“…Even in CS materials, a combination of strong spin-orbit (SO) coupling and disorder can have profound effects on the superconducting properties. The R 2 Pd x S 5 (x 1) family of materials where R = Nb or Ta with the CS space group C2/m are particularly noteworthy in this regard [22][23][24]. Strong SO coupling, along with Anderson localization resulting from a level of disorder due to Pd deficiency, leads to highly anisotropic upper critical fields that in some cases far exceed the Pauli limit [e.g., Nb 2 Pd 0.81 S 5 , T c ∼ 6.6 K, and H c2 (0) along the b axis of 37 T] [22].…”

Superconductivity and the upper critical field in the chiral noncentrosymmetric superconductor NbRh2B2

“…A combination of disorder and strong spin-orbit coupling can lead centrosymmetric materials to develop unusual superconducting properties. R 2 Pd x S 5 (x ≤ 1) where R = Nb or Ta form a remarkable family of centrosymmetric compounds [26,27,28]. In Ta 2 Pd x S 5 (T c ∼ 6 K) disorder due to a Pd deficiency is introduced into the compound, giving rise to Anderson localisation.…”