Peng Rui, Ma Yandong, Zhang Shuai, Huang Baibiao, Dai Ying
School of Physics, State Key Laboratory of Crystal Materials , Shandong University , Shandanan Street 27 , Jinan 250100 , China.
J Phys Chem Lett. 2018 Jul 5;9(13):3612-3617. doi: 10.1021/acs.jpclett.8b01625. Epub 2018 Jun 19.
Two-dimensional valleytronic systems can provide information storage and processing advantages that complement or surpass those of conventional charge- and spin-based semiconductor technologies. The major challenge currently is to realize valley polarization for manipulating the valley degree of freedom. Here, we propose that valley polarization can be readily achieved in Janus single-layer MoSSe through magnetic doping, which is highly feasible in experiment. Due to inversion symmetry breaking combined with strong spin-orbit coupling (SOC), the pure single-layer MoSSe harbors an intriguing multivalleyed band structure and strong coupled spin and valley physics. After doping Cr/V, the long-sought valley polarization is successfully achieved with a remarkable energy difference of ∼0.06 eV upon switching on SOC. Furthermore, the valley polarization in Cr/V-doped single-layer MoSSe is tunable via strain engineering. Our work thus provides a promising platform for experimental studies and applications of the valleytronics.
二维谷电子学系统能够提供信息存储和处理方面的优势，这些优势可补充或超越传统的基于电荷和自旋的半导体技术。当前的主要挑战是实现谷极化以操控谷自由度。在此，我们提出通过磁掺杂可在Janus单层MoSSe中轻松实现谷极化，这在实验中具有高度可行性。由于反演对称性破缺与强自旋轨道耦合（SOC）相结合，纯单层MoSSe具有引人入胜的多谷能带结构以及强耦合的自旋和谷物理特性。掺杂Cr/V后，在开启SOC时成功实现了长期以来寻求的谷极化，其能量差约为0.06 eV，十分显著。此外，Cr/V掺杂单层MoSSe中的谷极化可通过应变工程进行调节。因此，我们的工作为谷电子学的实验研究和应用提供了一个有前景的平台。
