Field dependence of the superconducting gap in YPd2Sn: A μSR and NMR study

13th International Conference on Muon Spin Rotation, Relaxation and Resonance

Morenzoni, E.^1 ; Saadaoui, H.^1 ; Amato, A.^1 ; Baines, C.^1 ; Luetkens, H.^1 ; Pomjakushina, E.^2 ; Pikulski, M.^1,3 ; Shiroka, T.^1,3

Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, Villigen PSI

CH-5232, Switzerland^1

Laboratory for Developments and Methods, Paul Scherrer Institut, Villigen PSI

CH-5232, Switzerland^2

Laboratorium für Festkörperphysik, ETH-Hönggerberg, Zürich

CH-8093, Switzerland^3

关键词: Applied magnetic fields;    Field independents;    Magnetic penetration depth;    Muon spin rotation/relaxation;    Nuclear Magnetic Resonance (NMR);    Polycrystalline samples;    Superconducting gaps;    Temperature dependence;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/551/1/012027/pdf
DOI  :  10.1088/1742-6596/551/1/012027

来源: IOP

【 摘 要 】

We have performed muon spin rotation/relaxation and119Sn nuclear magnetic resonance (NMR) measurements to study the vortex state of polycrystalline samples of YPd2Sn (Tc 5.4 K), over a wide range of applied magnetic fields up to Bc2(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 ξGL(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)/(kBTc) 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 . We discuss the significance of this result.