Influence of the lateral confining potential on the ballistic electron transport in a quantum wire

A theoretical investigation of ballistic electron transport in a quantum wire with soft wall confinement is presented. A general method of the electron transmission calculation is proposed for structures with complicated geometries. The effects of the lateral guiding potential on ballistic transport are investigated using three soft wall confinement models and the results are compared with those obtained from the hard wall confinement approximation. It is shown that the calculated transmission coefficients are notably dependent on the lateral confining potential especially when the incident electron energy is larger than the energy of the second transverse mode. It is found that the transmission profile obtained from soft wall confinement models exhibits simpler resonance structures than that obtained from the hard wall confinement approximation. Our results suggest that only in the single-channel regime the hard wall confinement approximation can give reasonable results.