Interactions of moving charge with supported graphene in the presence of strain-induced pseudomagnetic field

Abstract

A two-component hydrodynamic model is used to investigate low-energy plasmon excitations within the K and K′ valleys of the π electron bands in doped graphene on a dielectric substrate by a slow charged particle moving parallel to the graphene in the presence of a strain-induced pseudomagnetic field in graphene. Calculations of the stopping and the image forces on the moving charge, as well as of the total electrostatic potential in the plane of graphene are performed. The simulation results indicate that the valley polarization of electrons in graphene resulting from the pseudomagnetic field and the electrostatic coupling between graphene and the supporting substrate both have important impact on the stopping and the image forces, affecting the maximum values and the peak positions of those forces, as well as the velocity threshold for the plasmon excitation. In addition, we also study the dependence of the amplitude and period of the wake potential oscillations on the pseudomagnetic field strength, the gap size between graphene and substrate, as well as the incident particle speed. In particular, our results show that the pseudomagnetic field exerts quite strong influence on the period of the wake potential oscillations at the above-threshold particle speeds, especially for small graphene-substrate gap sizes.