报告题目：Weak Antilocalization in Polycrystalline SnTe Films Deposited by Magnetron Sputtering

报告人：杨帆 副教授 （天津大学）

报告时间：2022 年 10 月 7 日（周五）15：30

报告地点：在线报告（ 腾讯会议 ID : 533-369-677 ）

报告摘要：

Previous works on weak antilocalization (WAL) of SnTe were mostly carried out in MBE-grown films, where the signals of WAL usually coexist with a large parabolic background of classical magnetoresistance. In this article, we present our study on WAL in polycrystalline SnTe films deposited by magnetron sputtering. Due to the polycrystalline nature and the relatively low mobility of the films, the background of conventional magnetoresistance was greatly suppressed, and clean WAL signals, which are well described by the Hikami–Larkin–Nagaoka equation, were obtained at low temperatures. A close analysis of the WAL data shows that the number of transport channels contributing to WAL increases monotonously with decreasing temperatures, reaching N = 2.8 at T = 1.6 K in one of the devices, which indicates the decoupling of Dirac cones at low temperatures. Meanwhile, as the temperature decreases, the temperature dependence of phase coherence length gradually changes from l_phi ~ T^(-1) to l_phi ~ T^(-0.5), suggesting that the dominant mechanism of phase decoherence switches from electron–phonon scattering to electron–electron scattering. Our results are helpful for understanding the quantum transport properties of SnTe.

报告人简介：

杨帆，2007年本科毕业于南京大学物理系，2012年博士毕业于中科院物理所，2012-2018年先后在大阪大学和科隆大学从事博士后研究，2018年至今在天津大学物理系工作，主要研究方向为量子输运与量子器件。

参考文献：

[1]  X. Li, Y. Yang, X. Wang, P. Zhu, F. Qu, Z. Wang, and F. Yang, Crystals 12, 773 (2022).

[2]  B. A. Assaf,  F. Katmis, P. Wei, B. Satpati, Z. Zhang, S. P. Bennett, V. G. Harris, J. S. Moodera, D. Heiman, Appl. Phys. Lett. 105, 102108(2014).