Energetic derivation of the amplification of magnetic waves interacting with a flow of charges in a semiconductor

Abstract

The interaction between magnetic waves in a ferrite and drifting charges in a semiconductor is studied for flat geometries (slabs or plane surfaces), in view of identifying a possible amplification mechanism. This is done through an energetic formulation which gives the imaginary part of the wave propagation constant. Results are derived both for the transverse and the longitudinal magnetization and show that high gain values are theoretically possible. Along the way, the following interesting results have also been obtained: (i) the electromagnetic fields in the absence of interacting charges ("cold" fields) have been obtained for the surface magnetic wave (transverse propagation) together with the dispersion curve; (ii) the correct expressions of the rf fields have been calculated for the slab, both for the transverse and the longitudinal propagation.

Review and prospects of magnonic crystals and devices with reprogrammable band structure

“…Currents applied directly to a ferromagnetic device have the potential to modify the spin-wave spectrum. In heterostructures composed of uniform ferromagnetic, semiconductor and metallic films the interaction of unpolarized electric currents with spin waves was studied in the magnetostatic part of the spectrum and the possibility for spin-wave amplification was predicted [403][404][405][406][407][408]. Corresponding experimental data presented in [409] are however under discussion [27].…”

Interaction onde électromagnétique/flux de porteurs dans une structure mixte ferrite-semiconducteur

“…L'interaction cumulative d'une onde électromagnétique avec un flux de porteurs a été étudiée par de nombreux auteurs [1][2][3]. Elle a d'ailleurs servi de base théorique pour l'étude du comportement du tube à onde progressive [4].…”

Propagation des ondes électromagnétiques dans les milieux présentant une perméabilité et une conductivité tensorielles

“…Les autres géométries (Fig. 4b et 5) dont l'étude est plus complexe ont également été proposées pour réaliser de tels circuits [15][16]. Nous allons simplement montrer dans ce paragraphe que les modes qui se propagent dans de telles structures peuvent être obtenus par une combinaison des modes propres étudiés précédemment.…”