铁磁尖端诱导外尔半金属中的非常规超导性。

Ferromagnetic tip induced unconventional superconductivity in Weyl semimetal.

作者信息

Wang He, He Yingping, Liu Yiyuan, Yuan Zhujun, Jia Shuang, Ma Lei, Liu Xiong-Jun, Wang Jian

机构信息

International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Tianjin International Center for Nano Particles and Nano Systems, Tianjin University, Tianjin 300072, China; Department of Physics, Capital Normal University, Beijing 100048, China.

International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China; Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.

出版信息

Sci Bull (Beijing). 2020 Jan 15;65(1):21-26. doi: 10.1016/j.scib.2019.11.010. Epub 2019 Nov 13.

DOI:10.1016/j.scib.2019.11.010

PMID:36659064

Abstract

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 TaAs 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.

摘要

正常外尔半金属中金属尖端诱导的超导性为研究拓扑超导提供了一个很有前景的平台，而拓扑超导目前是凝聚态物理的一个研究热点。在此，我们通过实验发现，在TaAs单晶中，铁磁尖端的硬点接触（PC）方法可以诱导出非常规超导性。对铁磁尖端诱导超导（FTISC）态的磁输运测量显示出量子振荡，这表明超导性是在拓扑非平凡的外尔半金属费米面中诱导产生的，并且表明了铁磁性与诱导超导性的兼容性。我们进一步测量了FTISC态的隧穿输运点接触谱（PCS），这些态可能具有非平凡拓扑结构。考虑到具有新型超导性的磁性外尔半金属在实验中难以实现，我们的结果展示了一条通过硬PC方法将拓扑半金属与铁磁性相结合来研究非常规超导性的新途径。