QUANTUM ELECTRON-TRANSPORT THROUGH NARROW CONSTRICTIONS IN SEMICONDUCTOR NANOSTRUCTURES

Detailed numerical results, with emphasis on the role of disorder and constriction geometry, are presented for the calculated conductance of quantum point contacts between high-mobility two-dimensional electron systems fabricated on semiconductor nanostructures. The conductance is calculated from the two-terminal multichannel transmission matrix formalism using the recursive single-particle Green's-function technique. The Green's functions are obtained recursively for a tight-binding two-dimensional disordered Anderson lattice model representing the constriction. The conductance is calculated as a function of the shape and the size of the constriction (i.e., its geometry) and the elastic disorder in the system.