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

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.

Automated summary

We investigate the influence of strain on the valley-polarized transmission of graphene using wave-function matching and the non-equilibrium Green's function technique. Our results show that increasing the width of the strained region and adjusting the extensional strain in the armchair and zigzag directions can improve valley polarization and transmission. Shear strain, however, does not affect transmission or valley polarization. Additionally, we find that enhancing the smoothness of the strain barrier can enhance valley-polarized transmission. Our findings offer new insights for the construction of graphene-based valleytronic and quantum computing devices using strain alone.