3-DIMENSIONAL SIMULATIONS OF QUANTUM TRANSPORT IN SEMICONDUCTOR NANOSTRUCTURES

We introduce the planar supercell method as a means for treating three -dimensional quantum transport in mesoscopic tunnel structures. Our mo del treats potential variations along the growth direction as well as the lateral directions. The flexibility of the method allows us to exa mine a variety of physical phenomena relevant to quantum transport, in cluding alloy disorder, interface roughness, defect, impurities, and z ero-dimensional, one-dimensional, and two-dimensional quantum confinem ent, in a variety of device geometries ranging from double barrier het erostructures to quantum wire electron waveguides. Using this method, we have studied the transport properties of double barrier heterostruc tures with alloy barriers, including the effect of clustering in the a lloy layers. We have also examined interface roughness in double barri er structures, and analyzed k(parallel-to) scattering and lateral loca lization. In addition, we have studied the transport properties of a q uantum wire electron waveguide, and explored its sensitivity to the ge ometry of waveguide openings.