论文标题
de haas-van alphen量子振荡探测的BASN5超导体中的非平凡拓扑状态
Nontrivial topological states in BaSn5 superconductor probed by de Haas-van Alphen quantum oscillations
论文作者
论文摘要
我们在此报告通过测量磁化，比热，de haas-van alphen（DHVA）效应探测的固有II型超导体BASN5（TC〜4.4 K）中的非平凡拓扑状态。第一原理计算揭示了Brillouin区域（BZ）Kz =π平面中H点的拓扑结节结构，可以通过旋转轨道耦合（SOC）掩盖，分别在Fermi水平以下和高于0.04 eV和0.14 eV的范围以下和高于Fermi水平以下。 SOC还会导致一对沿γ-A方向的狄拉克点，并位于费米水平的0.2 eV。 DHVA量子振荡的分析通过揭示非平凡的浆果相来支持计算，起源于三个孔和一个与形成Dirac锥体的频带有关的电子口袋。因此，我们的研究为研究超导性和非平凡拓扑状态之间的相互作用提供了极好的途径。
We report herein the nontrivial topological states in an intrinsic type-II superconductor BaSn5 (Tc ~ 4.4 K) probed via measuring the magnetizations, specific heat, de Haas-van Alphen (dHvA) effect and performing first principles calculations. The first principles calculations reveal a topological nodal ring structure centering at the H point in the kz = π plane of the Brillouin zone (BZ), which could be gapped by spin-orbit coupling (SOC), yielding rather small gaps below and above the Fermi level about 0.04 eV and 0.14 eV, respectively. The SOC also results in a pair of Dirac points along the Γ-A direction and located ~ 0.2 eV above the Fermi level. The analysis of the dHvA quantum oscillations supports the calculations by revealing nontrivial Berry phase originated from three hole and one electron pockets related to the bands forming the Dirac cones. Our study thus provides an excellent avenue for investigating the interplay between superconductivity and nontrivial topological states.
