Valley-polarized and enhanced transmission in graphene with a smooth strain profile

Sake Wang; Hongyu Tian; Minglei Sun

doi:10.1088/1361-648X/accbf9

Valley-polarized and enhanced transmission in graphene with a smooth strain profile

J Phys Condens Matter. 2023 Apr 27;35(30). doi: 10.1088/1361-648X/accbf9.

Authors

Sake Wang¹, Hongyu Tian², Minglei Sun³

Affiliations

¹ College of Science, Jinling Institute of Technology, Nanjing 211169, People's Republic of China.
² School of Physics and Electronic Engineering, Linyi University, Linyi 276005, People's Republic of China.
³ Department of Physics and NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.

PMID: 37040781
DOI: 10.1088/1361-648X/accbf9

Abstract

We explore the influence of strain on the valley-polarized transmission of graphene by employing the wave-function matching and the non-equilibrium Green's function technique. When the transmission is along the armchair direction, we show that the valley polarization and transmission can be improved by increasing the width of the strained region and increasing (decreasing) the extensional strain in the armchair (zigzag) direction. It is noted that the shear strain does not affect transmission and valley polarization. Furthermore, when we consider the smooth strain barrier, the valley-polarized transmission can be enhanced by increasing the smoothness of the strain barrier. We hope that our finding can shed new light on constructing graphene-based valleytronic and quantum computing devices by solely employing strain.

Keywords: deformation-induced gauge field; graphene; non-equilibrium Green’s function; smooth strain profile; tight-binding model; valleytronics; wave-function matching.