Electrically controllable cyclotron resonance

TL;DR

This paper investigates how the cyclotron resonance in a gated 2D electron system can be electrically controlled, revealing a tunable redshift in the resonance frequency dependent on electron density and gate voltage.

Contribution

It demonstrates the controllability of cyclotron resonance in gated 2D electron systems through gate voltage modulation, introducing a new way to manipulate this fundamental phenomenon.

Findings

Redshift of absorption peak compared to electron cyclotron frequency

Redshift depends on electron density and can be controlled electrically

Potential for large shifts in realistic 2DES devices

Abstract

Cyclotron resonance (CR) is considered one of the fundamental phenomena in conducting systems. In this paper, we study CR in a gated two-dimensional (2D) electron system (ES). Namely, we analyze the absorption of electromagnetic radiation incident normal to the gated 2DES, where a standard dielectric substrate separates the 2D electron sheet and the metallic steering electrode ("gate"); the whole system is placed in the perpendicular magnetic field. Our analysis reveals the redshift of the absorption peak frequency compared to the electron cyclotron frequency. The redshift appears in low-frequency regime, when the resonant frequency is much less than the frequency of Fabry-Perot modes in natural resonator "2D electron sheet - substrate - gate". Moreover, we find this shift to be dependent on the electron density of 2DES. Therefore, it can be controlled by varying the gate voltage. We predict that the shift can be large in realistic gated or back-gated 2DESs. The obtained controllability of CR in gated 2DES opens the door for exploring new physics and applications of this phenomenon.