Weißhaupt David, Funk Hannes S, Kern Michal, Dettling Marco M, Schwarz Daniel, Oehme Michael, Sürgers Christoph, van Slageren Joris, Fischer Inga A, Schulze Jörg
Institute of Semiconductor Engineering (IHT), University of Stuttgart, Stuttgart, Germany.
Institute of Physical Chemistry (IPC), University of Stuttgart, Stuttgart, Germany.
J Phys Condens Matter. 2021 Feb 24;33(8):085703. doi: 10.1088/1361-648X/abcb68.
Low-temperature magnetoresistance measurements of n- and p-doped germanium-tin (Ge Sn ) layers with Sn concentrations up to 8% show contributions arising from effects of weak localization for n-type and weak antilocalization for p-type doped samples independent of the Sn concentration. Calculations of the magnetoresistance using the Hikami-Larkin-Nagaoka model for two-dimensional transport allow us to extract the phase-coherence length for all samples as well as the spin-orbit length for the p-type doped samples. For pure Ge, we find phase-coherence lengths as long as (349.0 ± 1.4) nm and (614.0 ± 0.9) nm for n-type and p-type doped samples, respectively. The phase-coherence length decreases with increasing Sn concentration. From the spin-orbit scattering length, we determine the spin-diffusion scattering length in the range of 20-30 nm for all highly degenerate p-type doped samples irrespective of Sn concentration. These results show that Ge Sn is a promising material for future spintronic applications.
对锡（Sn）浓度高达8%的n型和p型掺杂锗锡（GeSn）层进行的低温磁阻测量表明，对于n型掺杂样品，弱局域化效应会产生贡献；对于p型掺杂样品，弱反局域化效应会产生贡献，且这些贡献与Sn浓度无关。使用二维输运的日高-拉金-永冈模型对磁阻进行计算，使我们能够提取所有样品的相位相干长度以及p型掺杂样品的自旋轨道长度。对于纯锗，我们分别发现n型和p型掺杂样品的相位相干长度长达(349.0 ± 1.4)纳米和(614.0 ± 0.9)纳米。相位相干长度随Sn浓度的增加而减小。从自旋轨道散射长度来看，对于所有高度简并的p型掺杂样品，无论Sn浓度如何，我们确定其自旋扩散散射长度在20 - 30纳米范围内。这些结果表明，锗锡是未来自旋电子学应用的一种有前景的材料。
