论文标题
过渡金属二北菌单层中的飞秒电流
Femtosecond currents in transition metal dichalcogenides monolayers
论文作者
论文摘要
从理论上讲，我们研究了超快速的线性极化光脉冲与过渡金属二核苷（TMDC）的单层的相互作用。如此强的脉冲将电子重新分布在频带之间，并在脉冲过程中产生飞秒电流。由于入射脉冲的带宽很大，因此该过程完全偏离。虽然在TMDC中保守了时间反转对称性，但反转对称性被打破，这些单层具有沿扶手椅方向的轴向对称性，但沿锯齿形的对称性则不沿锯齿形。因此，沿TMDC单层的不对称方向极化的脉冲会产生纵向，即沿极化方向和横向，即在垂直方向，电流。这样的电流导致通过系统的电荷传输。我们研究了不同的TMDC材料，并展示了TMDC单层中的飞秒运输如何依赖其参数，例如晶格常数和带隙。
We theoretically study the interaction of an ultrafast intense linearly polarized optical pulse with monolayers of transition metal dichalcogenides (TMDCs). Such a strong pulse redistributes electrons between the bands and generates femtosecond currents during the pulse. Due to the large bandwidth of the incident pulse, this process is completely off-resonant. While in TMDCs the time-reversal symmetry is conserved, the inversion symmetry is broken and these monolayers have the axial symmetry along armchair direction but not along the zigzag one. Therefore, the pulse polarized along the asymmetric direction of TMDC monolayer generates both longitudinal, i.e., along the direction of polarization, and transverse, i.e., in the perpendicular direction, currents. Such currents result in charge transfer through the system. We study different TMDC materials and show how the femtosecond transport in TMDC monolayers depend on their parameters, such as lattice constant and bandgap.
