Theoretical Transport Studies of Non-equilibrium Carriers Driven by High Electric Fields.

摘要

This work examines quantum transport in nanowires with several different formalisms. The Boltzmann equation based theory of Lyo and Huang is able to incorporate many different kinds of scattering and make interesting predictions but found absent in it a simple way of providing physical understanding of its effects. The STM theory of Kenkre, Biscarini, and Bustamante incorporates incoherent scattering in a much simpler way, but difficulties arise when the motion is fully coherent. Wigner functions, which are quasi-probability distributions defined on phase space, are appealing because of the conceptual similarity to classical transport theory. Calculated the Wigner function for ballistic 1D conductors and show that the current reduces to the Landauer result, but incorporating boundary conditions correctly in more complicated cases remains a problem to complete. Found the transmission formalism to be quite useful for simpler systems with elastic scattering when the motion is fully coherent and have provided analysis of interactions of the conductor with a bath represented in a simple manner by harmonic vibrations.