Large magnetoresistance dips and perfect spin-valley filter induced by topological phase transitions in silicene

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:452

Article

Prarokijjak, Worasak¹  Soodchomshom, Bumned¹ 

[1] Kasetsart Univ, Fac Sci, Dept Phys, Bangkok 10900, Thailand

关键词: Silicene;    Topological phase transition;    Spin-valley filter;    Magnetoresistance;   

DOI  :  10.1016/j.jmmm.2018.01.004

来源: Elsevier

【 摘 要 】

Spin-valley transport and magnetoresistance are investigated in silicene-based N/TB/N/TB/N junction where Nand TB are normal silicene and topological barriers. The topological phase transitions in TB's are controlled by electric, exchange fields and circularly polarized light. As a result, we find that by applying electric and exchange fields, four groups of spin-valley currents are perfectly filtered, directly induced by topological phase transitions. Control of currents, carried by single, double and triple channels of spinvalley electrons in silicene junction, may be achievable by adjusting magnitudes of electric, exchange fields and circularly polarized light. We may identify that the key factor behind the spin-valley current filtered at the transition points may be due to zero and non-zero Chern numbers. Electrons that are allowed to transport at the transition points must obey zero-Chern number which is equivalent to zero mass and zero-Berry's curvature, while electrons with non-zero Chern number are perfectly suppressed. Very large magnetoresistance dips are found directly induced by topological phase transition points. Our study also discusses the effect of spin-valley dependent Hall conductivity at the transition points on ballistic transport and reveals the potential of silicene as a topological material for spin-valleytronics. (C) 2018 Elsevier B.V. All rights reserved.

【 授权许可】

Free