Incident-angle dependence of catastrophic dechanneling for strained-layer superlattices.

A strong asymmetry has been observed in the angular dependence of the catastrophic dechanneling depth in strained-layer superlattices. This new effect occurs under resonance conditions, where the wavelength of the planar channeled particles equals the period of the superlattice, and is demonstrated for )110) planar channeling in GaP/GaAs/sub x/P/sub 1-x/. A theoretical, phase-plane analysis shows that the angular tilt required for shifting of the catastrophic depth by one layer is a direct measure of the strain in the first few layers.