Date of Award

1-1-2010

Document Type

Campus Access Dissertation

Department

Physics and Astronomy

Sub-Department

Physics

First Advisor

Richard J Creswick

Abstract

In this work, we investigate the charge, or Loschmidt echo of a system of spinless electrons described by a simple tight-binding Hamiltonian. For this system it is possible to construct a unitary operator, T, that reverses the time evolution of the electron degrees of freedom. The electron gas is prepared in an initially inhomogeneous state. After a free evolution for a time t0, the electrons are distributed more or less uniformly, and the unitary operator, T is applied. The time evolution is reversed, and at time 2t0 the local density returns to its initial value, demonstrating the Loschmidt echo. The effect of several factors that reduce the strength of the echo are considered: imperfect implimentaton of T, second-neighbor hopping terms, and coupling the electron to phonons.

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