Toward adaptive control of coherent electron transportin semiconductors

摘要

This work explores the feasibility of using shaped electrostatic potentials to achieve specified finalscattering distributions of an electron wave packet in a two dimensional subsurface plane of asemiconductor. When electron transport takes place in the ballistic regime, and features of thescattering potentials are smaller than the wavelength of the incident electron then coherent quantumeffects can arise. Simulations employing potential forms based on analogous optical principlesdemonstrate the ability to manipulate quantum interferences in two dimensions. Simulations arepresented showing that suitably shaped electrostatic potentials may be used to separate an initiallylocalized Gaussian wave packet into disjoint components or concomitantly to combine a highlydispersed packet into a compact form. The results also indicate that highly complex scatteringobjectives may be achieved by utilizing adaptive closed-loop optimal control in the laboratory todetermine the potential forms needed to manipulate the scattering of an incoming wave packet. Anadaptive feedback algorithm can be used to vary individual voltages of multipixel gates on thesurface of a solid state structure to thereby find the potential features in the transport plane neededto produce a desired scattering objective. A proposed experimental design is described for testing theconcept of adaptive control of coherent electron transport in semiconductors.