Institute for Theoretical Physics, ETH Zurich, 8093 Zürich, Switzerland.
College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
Phys Rev Lett. 2018 Oct 19;121(16):166802. doi: 10.1103/PhysRevLett.121.166802.
Topological nodal-line semimetals are predicted to exhibit unique drumheadlike surface states (DSSs). Yet, direct detection of such states remains a challenge. Here, we propose spin-resolved transport in a junction between a normal metal and a spin-orbit coupled nodal-line semimetal as the mechanism for their detection. Specifically, we find that in such an interface the DSSs induce resonant spin-flipped reflection. This effect can be probed by both vertical spin transport and lateral charge transport between antiparallel magnetic terminals. In the tunneling limit of the junction, both spin and charge conductances exhibit a resonant peak around zero energy, providing unique evidence of the DSSs. This signature is robust to both dispersive DSSs and interface disorder. Based on numerical calculations, we show that the scheme can be implemented in the topological semimetal HgCr_{2}Se_{4}.
拓扑节线半导体预计会表现出独特的鼓形表面态（DSS）。然而，对这些状态的直接检测仍然是一个挑战。在这里，我们提出在正常金属和自旋轨道耦合节线半导体之间的结中进行自旋分辨输运作为检测它们的机制。具体来说，我们发现，在这种界面中，DSS 会诱导共振自旋翻转反射。这种效应可以通过垂直自旋输运和反平行磁端之间的横向电荷输运来探测。在结的隧道极限下，自旋和电荷电导都在零能量附近呈现出共振峰，为 DSS 提供了独特的证据。这种特征对分散的 DSS 和界面无序都具有鲁棒性。基于数值计算，我们表明该方案可以在拓扑半导体 HgCr2Se4 中实现。
