Das Debarchan, Gupta Ritu, Baines Christopher, Luetkens Hubertus, Kaczorowski Dariusz, Guguchia Zurab, Khasanov Rustem
Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland.
Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Wrocław, ul. Okólna 2, 50-422, Poland.
Phys Rev Lett. 2021 Nov 19;127(21):217002. doi: 10.1103/PhysRevLett.127.217002.
We investigated the superconducting properties of the topological superconductor α-PdBi_{2} at ambient and external pressures up to 1.77 GPa using muon spin rotation experiments. The ambient pressure measurements evince a fully gapped s-wave superconducting state in the bulk of the specimen. Alternating current magnetic susceptibility and muon spin rotation measurements manifest a continuous suppression of T_{c} with increasing pressure. In parallel, we observed a significant decrease of superfluid density by ∼20% upon application of external pressure. Remarkably, the superfluid density follows a linear relation with T_{c}, which was found before in some unconventional topological superconductors and hole-doped cuprates. This finding signals a possible crossover from Bose-Einstein to Bardeen-Cooper-Schrieffer like condensation in α-PdBi_{2}.
我们使用μ子自旋旋转实验研究了拓扑超导体α-PdBi₂在环境压力和高达1.77 GPa的外部压力下的超导特性。环境压力测量表明，样品主体中存在完全能隙的s波超导态。交流磁化率和μ子自旋旋转测量表明，随着压力增加，Tₑ持续降低。同时，我们观察到施加外部压力后超流密度显著下降约20%。值得注意的是，超流密度与Tₑ呈线性关系，这在一些非常规拓扑超导体和空穴掺杂铜酸盐中也曾被发现。这一发现表明α-PdBi₂中可能存在从玻色-爱因斯坦凝聚到巴丁-库珀-施里弗凝聚的转变。
