CONDUCTION-BAND MIXING IN T-SHAPED AND V-SHAPED QUANTUM WIRES

By means of a tight-binding approach, we have studied the influence of barrier states on the conduction band of the T-and V-shaped quantum w ires. For AlAs/GaAs superlattices or pure AlAs barriers, X-related sta tes induce strong modifications in the wire conduction band that canno t be accounted For by a simple effective-mass approximation. With resp ect to quantum wells, we show that the quasi-one-dimensional confineme nt of quantum wires enhances valley mixing and leads to a reduction in the energy of lower lying states.