Quantum wires in staggered-band-line-up single heterostructures with corrugated interfaces

The spatial shape of the conduction- and valence-band edges of type-II heterojunctions in V grooves is calculated self-consistently. Quantum wires are formed in the groove center only by means of a deformed potential shape without any further structural confinement. The quantum-wire potential is attractive for one type of charge carrier only and repulsive for the other type. The influence of structural parameters on the formation of the wire and on the quantum states is studied. As a model system we use InP on ${\mathrm{In}}_{0.48}$${\mathrm{Al}}_{0.52}$As in which an electron wire is formed. Structures with periodic arrays of grooves that exhibit a significantly deeper lateral potential than single grooves are investigated. In those structures an influence of the adjacent side quantum well can no longer be observed. We find here a subband splitting somewhat smaller than kT at room temperature and strongly depending on the ``sharpness'' of the groove tip. A comparison of self-consistent calculations and the often used semiclassical calculations shows that the latter method is liable to produce incorrect quantitative results.