Valleytronic device based on graphene is recently attracting growing interest because of its potential applications such as in quantum information storage and transmission. However, one of the major challenges in designing valleytronic devices is to realize the large valley polarization. Therefore, in the present work, we investigate the effect of the electrostatic barrier on the valley polarization in a graphene modulated by two ferromagnetic metal stripes and one strain, where the large valley polarization can be achieved due to the effect of the electrostatic barrier. With the increase in the height or the width of the electrostatic barrier, the degree of the valley polarization will greatly increase. These interesting finds are very helpful for understanding the valley-dependent transport mechanism of electrons in graphene and designing the valleytronic devices based on graphene under the modulation of the electrostatic barrier.

基于石墨烯的 Valleytronic 设备最近因其在量子信息存储和传输等方面的潜在应用而引起越来越多的兴趣。然而，设计谷电子器件的主要挑战之一是实现大谷极化。因此，在目前的工作中，我们研究了静电势垒对由两个铁磁金属条和一个应变调制的石墨烯中谷极化的影响，其中由于静电势垒的影响可以实现大谷极化。随着静电势垒高度或宽度的增加，谷极化程度将大大增加。