Anisotropy of the confined hole states in a (311)A AlAs/GaAs/AlAs quantum-well system: Evidence for a camel’s-back band structure

Magnetic fields applied parallel to the layer interfaces are used to examine the in-plane energy-band dispersion and anisotropy of the quantum-well states of a double-barrier AlAs/GaAs/AlAs resonant-tunneling diode grown on a (311)A-oriented substrate. The measurements reveal biaxial anisotropy in several of the subbands, some of which have a ‘‘camel’s-back’’-shaped structure. These features are confirmed by a six-component envelope-function calculation of the subbands of a (311) valence-band quantum well.