A controllable valley polarization in Graphene

TL;DR

This paper demonstrates a method to achieve complete and controllable valley polarization in graphene using a resonator made of line-defects, enabling potential applications in valleytronics.

Contribution

It introduces a novel resonator design with line-defects that allows for tunable and 100% valley polarization in graphene, advancing valleytronics technology.

Findings

Complete valley polarization can be achieved and controlled.

The incident angle for polarization can be tuned via resonator parameters.

The method is feasible with current experimental techniques.

Abstract

The electron transport of different conical valleys is investigated in graphene with extended line-defects. Intriguingly, the electron with a definite incident angle can be completely modulated into one conical valley by a resonator which consists of several paralleling line-defects. The related incident angle can be controlled easily by tuning the parameters of the resonator. Therefore, a controllable 100% valley polarization, as well as the detection of the valley polarization, can be realized conveniently by tuning the number of line-defects and the distance between two nearest neighbouring line-defects. This fascinating finding opens a way to realize the valley polarization by line-defects. With the advancement of experimental technologies, this resonator is promising to be realized and thus plays a key role in graphene valleytronics.