Magnetoplasmon-Mediated Resonant Photogalvanic Effect in a Gated Strip of 2D Electrons

TL;DR

This paper theoretically explores how magnetoplasmon resonances in a gated 2D electron strip induce a nonlinear photogalvanic effect, producing a DC current and voltage with behaviors analogous to the classical Hall effect.

Contribution

It provides an analytical model of the nonlinear photogalvanic response mediated by magnetoplasmons in a gated 2D electron system under magnetic field.

Findings

Resonant magnetoplasmon excitation induces a DC current and voltage.

The photovoltage follows a monotonic relation with magnetic field.

The photocurrent shows a minimum at specific wavevector directions.

Abstract

We theoretically investigate a nonlinear response to a linearly polarized monochromatic electromagnetic wave incident at an angle on a two-dimensional (2D) electronic system (ES) in the form of an infinite strip. The 2D ES is situated on a dielectric substrate near a perfectly conducting metal electrode (gate). The entire system is subjected to an external perpendicular constant magnetic field. We use Maxwell's equations for electromagnetic waves, while the electrons are described within the hydrodynamic approximation using Euler's equations and neglecting electromagnetic retardation effects. The incident electromagnetic wave excites magnetoplasmons in the strip. The fully screened limit is considered when all characteristic dimensions of the system, including the plasmon wavelengths, are much larger than the distance to the gate. This limit allows the linear response to be determined fully analytically. Due to the nonlinear hydrodynamic (convective) term, the excited magnetoplasmon oscillations give rise to a DC current along the strip and a voltage across it. Surprisingly, the relationship between the photocurrent and the photovoltage in resonance is exactly the same as in the classical Hall effect. The photovoltage is a monotonic function of the magnetic field. However, the photocurrent exhibits a minimum, which occurs at specific wavevector directions.