Abstract In this work we investigate the effects of a Fermi velocity modulation in a valley filter in graphene created by a combination of a magnetic and electric barrier. With the effective Dirac equation of the system, we use the transfer matrix formalism to obtain the transmittance. We verify that the valley transport in graphene is very sensitive to a Fermi velocity modulation, which is able to choose which valley will be filtered with perfect filtering. Also, it is possible to use a Fermi velocity modulation to filter both valleys or to make the valley filter transparent. It reveals that the Fermi velocity is a powerful tool that can be used to tune a graphene valley filter, since it has a total control in its transport properties.

中文翻译：

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由石墨烯中的费米速度调制控制的完美谷滤波器

摘要 在这项工作中，我们研究了由磁势垒和电势垒组合产生的石墨烯谷滤波器中费米速度调制的影响。借助系统的有效狄拉克方程，我们使用传递矩阵形式来获得透射率。我们验证了石墨烯中的谷传输对费米速度调制非常敏感，费米速度调制能够选择通过完美过滤来过滤哪个谷。此外，可以使用费米速度调制来过滤两个谷或使谷过滤器透明。它表明费米速度是一种强大的工具，可用于调整石墨烯谷滤波器，因为它可以完全控制其传输特性。