论文标题
纯且坚固的拓扑$α$ -SN膜中的非平凡量子磁转移振荡
Non-trivial quantum magnetotransport oscillations in pure and robust topological $α$-Sn films
论文作者
论文摘要
我们报告了在INSB底物上生长的纯净和健壮的$α$ -SN膜中拓扑dirac fermion荷载体的实验证据。使用标准的宏观四点接触电阻测量获得了该证据，该测量在没有大量迁移率的非封闭膜上进行。我们分析并比较了$α$ -SN/INSB样品的组成组件的电特性，并相应地提出了三波段漂移速度模型。具有低载体密度和高迁移率的表面带被确定为观察到的Shubnikov -de Haas振荡的起源。对这些量子振荡的分析导致相移$γ= 0 $的非平凡值，这是拓扑受保护的迪拉克费米子的特征。对于相同的未盖样品，我们估计动量放松时间$τ\约300 \ \ mathrm {fs} $，与先前关于$α$ -SN胶片的报告相比，它比以前的报告要大得多。
We report experimental evidence of topological Dirac fermion charge carriers in pure and robust $α$-Sn films grown on InSb substrates. This evidence was acquired using standard macroscopic four-point contact resistance measurements, conducted on uncapped films with a significantly reduced bulk mobility. We analyzed and compared electrical characteristics of the constituting components of the $α$-Sn/InSb sample, and propose a three-band drift velocity model accordingly. A surface band, with low carrier density and high mobility, is identified as the origin of the observed Shubnikov -- de Haas oscillations. The analysis of these quantum oscillations results in a non-trivial value of the phase shift $γ=0$, characteristic for topologically protected Dirac fermions. For the same uncapped samples we estimate the momentum relaxation time $τ\approx 300\ \mathrm{fs}$, which is significantly larger in comparison with the previous reports on grown $α$-Sn films.
