Acoustoelectric Current in Graphene Nanoribbon due to Landau Damping

Abstract

We perform self-consistent analysis of the Boltzmann transport equation for momentum and energy in the hypersound regime i.e., ql >> 1 (q is the acoustic wavenumber and l is the mean free path). Here, we investigate Landau damping of acoustic phonons (LDOAP) in graphene nanoribbon that leads to acoustoelectric current generation. Under a non-quantized field with drift velocity, we observed an acoustic phonon energy quantization which depends on the energy gap, the width and the sub-index of the material. An effect similar to Cerenkov emission was observed where the electron absorbs the confined acoustic phonons energy, causing the generation of acoustoelectric current in Graphene Nanoribbon. A qualitative analysis of the absorption and versus phonon frequency is in agreement with experimental reports. We observed a shift in the peaks when the energy gap and the drift velocity were varied. Most importantly, a transparency window appears when making graphene nanoribbon a potential candidate as an acoustic wave filter with applications in phonon spectrometers and also as tunable gate-controlled quantum information device.

Giant quantum oscillations of acoustoelectric current in narrow graphene nanoribbons

“…This energy gap opens due to the quantum confinement of electrons in the GNR. As shown in [26], in the presence of an external dc electric field causing the drift of electrons with a velocity v D , the strain provided by the SAW leads to the band gap ∆ ac , which is determined by the equation…”