Spin valve effect and hall resistance in a wide parabolic well

Abstract

We report observation of the Hall slope change in wide Al c Ga 1−c As parabolic wells in the presence of a quasi-parallel magnetic field. Above the critical magnetic field B > 4T , the Hall resistance becomes temperature dependent and can be described by equation R xy /cosΘ ∼ (B − B 0 )/en s , where n s is the electron density, B 0 =2-2.6 T and Θ is the angle between magnetic field and the normal to the well plane. The effect strongly depends on the electron density; it is observed only in parabolic wells, which are almost completely filled by electrons. We attribute the Hall slope change to the unusual behaviour of the effective g f actor in such parabolic well, which depends on the Al composition and changes the sign along the well width.

O transistor válvula de spin de AlGaAs/GaAs e outros semicondutores: dirigido a novos dispositivos spintrônicos

“…Assim, dentro do intervalo de interesse, pode-se considerar que o fator g em estruturas de Al x Ga 1−x As muda com a composição x de Al em forma linear [53,54], comoé mostrado na Fig. (1.17) [53].…”