OFF-RESONANCE GAMMA-CHI MIXING IN SEMICONDUCTOR QUANTUM WIRES

We present a theoretical study of the electronic states in T-, L-, and V-shaped realistic quantum wires taking into account Gamma-X mixing i n the conduction band. Calculations are based on two different approac hes, namely, a tight-binding and a multivalley envelope function (MVEF ) technique. A strong reduction of the electron energy due to the off- resonant Gamma-X mixing has been found in all types of quantum wires. This effect appears to be enhanced by a strong localization of the ele ctron wave function and by a strong overlap with atomic layers next to heterointerfaces. The remarkable agreement between the results obtain ed within the two approaches proves the validity of MVEF methods over a wide range of one-dimensional heterosystems. [S0163-1829(98)05416-2] .