Inhomogeneous boundary effects in semiconductor quantum wires

摘要: Boundary effects play an essential role in determining the physical properties of semiconductor quantum wires. Additional features come into when one considers inhomogeneous boundaries, i.e. wires whose widths are functions distance along length wire. The authors show that, adiabatic approximation (which assumes that boundary potential fluctuation effects, or equivalently, variations wire width, occur on a scale much larger than inverse Fermi wavelength), problem for is equivalent to one-dimensional Schrodinger equation with: (i) effective provided by deviation from homogeneous and, (ii) wave function coupled lateral direction. In periodic case, subbands system split many mini-subbands, and become useful test 1D band theory. When fluctuates randomly, there exists each subbands, mobility edge, below which electron states localized. localization tail top populated makes conductance drop smoothly whenever energy passes bottom new subband. theory explains recent experiments Smith Craighead (1990).