Spatial dispersion of magnetic-edge magnetoplasmons: Effect of semi-infinite gate

TL;DR

This paper investigates the spatial dispersion of magnetic-edge magnetoplasmons in a 2D electron system influenced by a semi-infinite metallic gate and ferromagnetic film, revealing unconventional dispersion relations and potential resonance effects.

Contribution

It introduces a detailed analysis of MEMPs affected by semi-infinite gates and ferromagnetic films, highlighting their localized nature and unique dispersion characteristics.

Findings

Strong spatial dispersion of fast MEMPs due to metallic gate

Localization of MEMPs near the metallic wedge edge

Hysteresis effects significantly influence phase velocities

Abstract

Magnetic-edge magnetoplasmons (MEMPs) are obtained for a two-dimensional electron system (2DES) with atop semi-infinite metallic gate, at a distance $d$, and atop semi-infinite ferromagnetic film at a strong perpendicular magnetic field. For two most fast MEMPs, one with positive chirality and other with negative chirality, a strong spatial dispersion, due to effect of metallic half-plane gate, is obtained; some slower MEMPs manifest spatial dispersion too. Present MEMPs are localized at the magnetic-edge that is close to the wedge of metallic half-plane gate; the metallic wedge enhances localization of MEMPs at magnetic-edge. Obtained spatial dispersion has unconventional form. In particular, for two most fast MEMPs the phase velocities, $\omega/k_{x}$, are the linear polynomials on the wave vector $k_{x}$ in the long-wavelength region, $k_{x}d \ll 1$. Strong effect of the ferromagnetic film hysteresis on the MEMPs phase velocities and their anti-crossings are obtained for $0<k_{x}d \leq1$. Two MEMPs of opposite chirality, especially two most fast MEMPs, at some resonance frequency can create a resonance circuit, with closed wave path along a fraction of the magnetic edge perimeter, with a total change of the wave phase given by an integer of $2\pi$.