外场作用下Weyl半金属中电子传输的类光性质研究

材料体系的拓扑量子行为是当前凝聚态物理研究的热点。作为一种新型拓扑量子态，Weyl半金属最近引起了人们广泛的关注。本项目首先讨论外加磁场对Weyl半金属中电子透射率和群时延的影响，揭示外加磁场对群时延的调制作用和对Hartman效应的影响，以及群时延和居留时间的关系；并进一步分析Goos-Hänchen位移对于群时延及Hartman效应的影响。其次研究应力作用下Weyl半金属势垒中电子在行波场下群时延的共振效应和消逝场下群时延的Hartman效应；导出应力作用下Weyl半金属势垒中居留时间和群时延之间的关系，并从中揭示Hartman效应的本质。最后研究外加时变外场作用下Weyl半金属中的光辅电子输运性质，探讨Weyl半金属中电子的透射几率、电导、散粒噪声、Fano因子和含时周期势强度、电子入射能量及势垒宽度之间的变化关系。研究结果可为以Weyl半金属为基础的电子器件设计提供有益的参考。

Currently, the topological behavior of materials is a hot topic in condensed matter physics. As a new class of topological quantum states, Weyl semimetals have attracted extensive interest. Firstly, in this project, we study the influences of the electron transmission and group delay time of the Weyl semimetals in the presence of the magnetic field, and further analysis the influence of Goos-Hänchen shift on the group delay time and the Hartman effect. Secondly, we study the transmission resonance effect of the group delay in the propagating case and the Hartman effect in the evanescent case in the presence of the strain field, and derive the relationship between the dwell time and the group delay time of the Weyl semimetals barrier in the presence of the strain field, to clarify the essence of the Hartman effect. Finally, we will investigate the transport properties of the photon-assisted electron tunneling in Weyl semimetals in the presence of the time-periodic potential, and discuss the relationship between the transmission probability, conductivity, shot noise and Fano factor of the Weyl semimetals and the time-periodic potential strength, the electron incident energy and the barrier width. Our results will facilitate the design of the Weyl semimetals-based electronic devices.