Novel Materials Group, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489, Berlin, Germany.
High Field Magnet Laboratory, Radboud University Nijmegen, P.O. Box 9010, 6500 GL, Nijmegen, Netherlands.
Sci Rep. 2018 Jan 11;8(1):485. doi: 10.1038/s41598-017-18960-0.
Helically spin-polarized Dirac fermions (HSDF) in protected topological surface states (TSS) are of high interest as a new state of quantum matter. In three-dimensional (3D) materials with TSS, electronic bulk states often mask the transport properties of HSDF. Recently, the high-field Hall resistance and low-field magnetoresistance indicate that the TSS may coexist with a layered two-dimensional electronic system (2DES). Here, we demonstrate quantum oscillations of the Hall resistance at temperatures up to 50 K in nominally undoped bulk BiSe with a high electron density n of about 2·10 cm. From the angular and temperature dependence of the Hall resistance and the Shubnikov-de Haas oscillations we identify 3D and 2D contributions to transport. Angular resolved photoemission spectroscopy proves the existence of TSS. We present a model for BiSe and suggest that the coexistence of TSS and 2D layered transport stabilizes the quantum oscillations of the Hall resistance.
在具有拓扑表面态 (TSS) 的三维 (3D) 材料中，电子体相态常常掩盖了螺旋极化狄拉克费米子 (HSDF) 的输运性质。最近，高磁场下的霍尔电阻和低磁场下的磁电阻表明 TSS 可能与层状二维电子系统 (2DES) 共存。在这里，我们在具有高电子密度 n 约为 2·10cm 的名义上未掺杂的 BiSe 中，在高达 50 K 的温度下，演示了霍尔电阻的量子振荡。从霍尔电阻的角度和温度依赖性以及舒布尼科夫-德哈斯振荡，我们确定了对输运的 3D 和 2D 贡献。角分辨光发射谱证明了 TSS 的存在。我们提出了一个 BiSe 的模型，并提出 TSS 和二维层状输运的共存稳定了霍尔电阻的量子振荡。
