Tunable valley filter efficiency by spin-orbit coupling in silicene nanoconstrictions

• 作者: Yi-Jian Shi Yuan-Chun Wang Peng-Jun Wang
• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2021,（5）
• 所属期刊栏目: CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES
• 页码范围: 663-669
• 页数: 7页
• 语种: 英文
• DOI: 10.1088/1674-1056/abcf35

摘要

Valley filter is a promising device for producing valley polarized current in graphene-like two-dimensional honey-comb lattice materials.The relatively large spin-orbit coupling in silicene contributes to remarkable quantum spin Hall effect,which leads to distinctive valley-dependent transport properties compared with intrinsic graphene.In this paper,quantized conductance and valley polarization in silicene nanoconstrictions are theoretically investigated in quantum spin-Hall insulator phase.Nearly perfect valley filter effect is found by aligning the gate voltage in the central constriction region.However,the valley polarization plateaus are shifted with the increase of spin-orbit coupling strength,accompa-nied by smooth variation of polarization reversal.Our findings provide new strategies to control the valley polarization in valleytronic devices.