On the plasmon dispersion in biased graphene bilayer

TL;DR

This paper investigates how bias voltage influences plasmon dispersion in doped graphene bilayer, revealing controllable and nonmonotonous curvature changes with a critical bias point dependent on carrier concentration.

Contribution

It demonstrates the ability to control plasmon dispersion curvature in graphene bilayer via bias voltage, including the identification of a nonmonotonous dependence and a critical breaking point.

Findings

Bias voltage affects plasmon dispersion curvature.

A nonmonotonous dependence with a breaking point is predicted.

Breaking point bias voltage scales with the square root of carrier concentration.

Abstract

Plasma oscillations in doped graphene bilayer at zero temperature has been investigated. Bias voltage effect on the dispersion curve for plasmon in bigraphene has been studied in random phase approximation. The possibility of controlling of curvature of dispersion curve for plasmon by changing of bias voltage has been shown. The dependence of this curvature on the bias voltage has been predicted to have the nonmonotonous character. Namely the existence of breaking point for such dependence has been found out. The bias voltage corresponding to the breaking point is shown to increase with free carriers concentration as square root of concentration.