Field dependence of the superconducting gap in YPd&lt;sub&gt;2&lt;/sub&gt;Sn: a &lt;em&gt;μ&lt;/em&gt;sR and NMR study

Morenzoni, E.; Saadaoui, H.; Amato, A.; Baines, C.; Luetkens, H.; Pomjakushina, E.; Pikulski, M.; Shiroka, T.

doi:10.1088/1742-6596/551/1/012027

Field dependence of the superconducting gap in YPd₂Sn: a μsR and NMR study

Morenzoni E, Saadaoui H, Amato A, Baines C, Luetkens H, Pomjakushina E, Pikulski M & Shiroka T

Citation

Morenzoni, E., Saadaoui, H., Amato, A., Baines, C., Luetkens, H., Pomjakushina, E., … Shiroka, T. (2014). Field dependence of the superconducting gap in YPd₂Sn: a μsR and NMR study. In Z. Salman, A. Amato, H. Luetkens, & E. Morenzoni (Eds.), Journal of physics: conference series: Vol. 551. 13th international conference on muon spin rotation, relaxation and resonance (μSR 2014) (p. 012027 (6 pp.). https://doi.org/10.1088/1742-6596/551/1/012027

Persistent URL https://www.dora.lib4ri.ch/psi/islandora/object/psi:22297

We have performed muon spin rotation/relaxation and ¹¹⁹Sn nuclear magnetic resonance (NMR) measurements to study the vortex state of polycrystalline samples of YPd₂Sn (T_c 5.4 K), over a wide range of applied magnetic fields up to B_c₂(T). Measurements in the vortex state provide the temperature dependence of the effective magnetic penetration depth λ(T) and the field dependence of the superconducting gap Δ(0). The results are consistent with a very dirty s-wave BCS superconductor with λ(0) 212(1) nm, a gap Δ(0) 0.85(3) meV, and a Ginzburg-Landau coherence length ξ_GL(0) ≅ 23 nm. The μSR data in a broad range of applied fields are well reproduced by taking into account a field-related reduction of the effective superconducting gap. Interestingly, the ratio 2Δ(0)/(k_BT_c) appears to a good approximation to be field-independent, with a value at low field of 3.85(9), implying a field dependence of the gap Δ(T = 0, B) = Δ(T = 0, B = 0)√1−B/Bc2(0). We discuss the significance of this result.