Robust valley filter induced by quantum constructive interference in graphene with line defect and strain. (1st December 2022)

• Record Type: Journal Article
• Authors: Du, L; Ren, C D; Cui, L; Lu, W T; Tian, H Y; Wang, S K
• Is Part Of: Physica scripta. Volume 97:Number 12(2022)
• Publication Date: 2022-12-01
• Subjects: valleytronics -- strain -- line defect -- quantum interference -- graphene -- non-equilibrium Green's function -- Anderson disorder; Physics -- Periodicals; 530.05
• DOI: 10.1088/1402-4896/ac9e7b
• Languages: English
• ISSNs: 0031-8949

Abstract

Abstract: In this paper, we theoretically investigate the manipulation of valley-polarized currents and the optical-like behaviours of Dirac fermions in graphene with single line defect. After the introduction of a local uniaxial strain, the valley transmission probability increases and transmission plateau emerges in a large angle range. Such phenomenon originates from resonant tunnelling, and the strain act as an antireflective coating for the valley states, analogous to the antireflective coating in an optical device. This indicates that perfect valley polarization can occur in a larger incident angle range compared with solely line defect. Interestingly, in the presence of Anderson disorder, even though the transmission decreases, the valley polarization is still robust. Our theoretical findings may be experimentally observable and valuable for valleytronic applications based on graphene.