# AlGaAs

## Quantum coherence in semiconductor superlattices

Using photocurrent spectroscopy, we have demonstrated that the quantum coherence in GaAs-Ga$_{1-x}$Al$_x$As superlattices increases with decreasing superlattice period $D$, and that it is maintained for at least eight periods when $D = 60$ angstroms. …

## Doubly Resonant Raman Scattering Induced by an Electric Field

By applying a variable electric field to a 30-35 Å GaAs/Ga$_{0.65}$Al$_{0.35}$As superlattice we have achieved tunable doubly resonant Raman processes, in which both the incident and the scattered light are in resonance with electronic transitions. …

## Stark Localization in GaAs-GaAlAs Superlattices under an Electric Field

We have observed that a strong electric field E shifts to higher energies the photoluminescence and photocurrent peaks of a GaAs-Ga0.65Al0.35As superlattice of period D (=65 Å), which we explain by a field-induced localization of carriers to isolated …