Muon spin relaxation\rotation study of a valence-skip and possible topological superconductor SnAs

We propose to measure high-quality single-crystal samples of SnAs, a possible new valence-skip and topological superconductor, SnAs, using a combination of zero-field (ZF) and transverse-field (TF)-µSR measurements. To the best of our knowledge, no microscopic measurements have been done to date to investigate the true nature of the superconducting ground state in this material. Here we proposed to map the superconducting phase diagram of this material by measuring the internal field distribution under different applied fields and temperature and confirm type-I/type-II superconductivity. ZF-µSR measurements will be performed to detect any tiny magnetism arising from the odd parity state, which breaks time-reversal symmetry. We ask for 4 days of MUSR beamtime to complete the experiment.

本研究拟结合零场（zero-field, ZF）与横向场（transverse-field, TF）µSR测试手段，对潜在新型价跳变拓扑超导体SnAs的高质量单晶样品开展表征。据我们所知，迄今为止尚无针对该材料超导基态本质的微观测量研究。本实验拟通过调控外加磁场与温度，测量其内部场分布，以此绘制该材料的超导相图，并验证其属于I型还是II型超导电性。我们将开展零场µSR测试，以探测由破坏时间反演对称性的奇宇称态所引发的微弱磁性信号。本实验申请4天的MUSR束流时间以完成全部实验。