摘要
The metallic tip-induced superconductivity in normal Weyl semimetal offers a promising platform to study topological superconductivity,which is currently a research focus in condensed matter physics.Here we experimentally uncover that unconventional superconductivity can be induced by hard point contact(PC)method of ferromagnetic tips in Ta As single crystals.The magneto-transport measurements of the ferromagnetic tip-induced superconducting(FTISC)states exhibit the quantum oscillations,which reveal that the superconductivity is induced in the topologically nontrivial Fermi surface of the Weyl semimetal,and show compatibility of ferromagnetism and induced superconductivity.We further measure the point contact spectra(PCS)of tunneling transport for FTISC states which are potentially of nontrivial topology.Considering that the magnetic Weyl semimetal with novel superconductivity is hard to realize in experiment,our results show a new route to investigate the unconventional superconductivity by combining the topological semimetal with ferromagnetism through hard PC method.
拓扑超导体由于具有独特的物理性质和在量子计算领域具有潜在应用价值而成为凝聚态物理领域的研究热点之一.而针尖诱导超导实验技术是研究基于拓扑材料的拓扑超导电性的重要实验手段.在本工作中,作者使用铁磁性金属针尖在外尔半金属Ta As单晶上,形成类似磁性外尔半金属的异质结构,并成功地诱导出超导电性.量子振荡、铁磁超导共存和非常规超导点接触谱型三方面实验数据的分析表明,铁磁针尖诱导的超导态具有非常规超导电性.结合理论模型,作者给出了拓扑超导的证据.这一工作丰富和完善了拓扑材料中针尖诱导拓扑超导的实验方法,并为拓扑超导方向提供了新的研究视角.
基金
financially supported by the National Key R&D Program of China (2018YFA0305604, 2017YFA0303302, and 2016YFA0301604)
the National Natural Science Foundation of China (11888101, 11774008, 0401210001, 11574008, 11761161003, 11825401, 11704279, 11774255, U1832214, and 11774007)
the Strategic Priority Research Program of Chinese Academy of Sciences (XDB28000000)
the Beijing Natural Science Foundation (Z180010)
the Key Project of Natural Science Foundation of Tianjin City (17JCZDJC30100)
China Postdoctoral Science Foundation (0401130005)
