Direct observation of $\Gamma -X$ energy spectrum transition in narrow AlAs quantum wells

Abstract

Spectra of magnetoplasma excitations have been investigated in a two-dimensional electron systems in AlAs quantum wells (QWs) of different widths. The magnetoplasma spectrum have been found to change profoundly when the quantum well width became thinner than $5.5$~nm, indicating a drastic change in the conduction electron energy spectrum. The transformation can be interpreted in terms of transition from the in-plane strongly anisotropic $X_x-X_y$ valley occupation to the out-of-plane isotropic $X_z$ valley in the QW plane. Strong enhancement of the cyclotron effective mass over the band value in narrow AlAs QWs is reported.

References in corpus (7)

• Two-dimensional electrons occupying multiple valleys in AlAs
• Spin susceptibility of two-dimensional electrons in narrow AlAs quantum wells
• Microwave response of a two-dimensional electron stripe
• Electron spin resonance on a 2-dimensional electron gas in a single AlAs quantum well
• Effective mass suppression upon complete spin-polarization in an isotropic two-dimensional electron system
• Interface Contributions to the Spin-Orbit Interaction Parameters of Electrons at the (001) GaAs/AlGaAs Interface
• Design rules for modulation-doped AlAs quantum wells

Cited by in corpus (3)

• Mobility and quantum mobility of modern GaAs/AlGaAs heterostructures
• Piezoplasmonics: strain-induced tunability of plasmon resonance in AlAs quantum wells
• Reduction of fully screened magnetoplasmons in a laterally confined anisotropic two-dimensional electron system to an isotropic one