Quantum electrodynamic shifts of mass and magnetic moment near dielectric or conducting surfaces

Bennett, Robert (2013) Quantum electrodynamic shifts of mass and magnetic moment near dielectric or conducting surfaces. Doctoral thesis (PhD), University of Sussex.

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Abstract

Quantum electrodynamics is the spectacularly successful theory of the interaction of light and matter. Its consequences are well-understood, and have been experimentally verified to extreme precision. What is not generally known is how these predictions change when the theory is considered in anything other than free space - near a surface, for example. A material boundary causes vacuum fluctuations of the electromagnetic field to be different from their counterparts in free space, causing the electromagnetic environment of a microscopic system sitting near the boundary to differ from that if the surface were
not present. This causes a variety of surface-dependent shifts in the properties of the microscopic system - this work investigates these shifts for a free electron. First using explicit normal mode expansion and analytic continuation of the wave-vector in the complex plane, and then using a semi-phenomenological `noise current' approach, the work presents derivations of formulae for the shifts in the mass and magnetic moment of an electron near a dispersive and absorbing surface. The formalism is also extended to the case where the electron is subject to a harmonic potential. It is noted that results for different models of the surface do not agree in the expected limiting cases due to their differing behaviour at low frequency, which leads to the conclusion that one must be very careful to use an appropriate model of a particular surface when considering quantum electrodynamic surface effects. Analysis of the results shows that use of a realistic model of the surface can make these shifts orders of magnitude larger than previous calculations had suggested, since they all relied on the somewhat unrealistic assumption that the surface is perfectly reflecting. This is shown to be particularly relevant to experiments which aim to measure
the anomalous magnetic moment of an electron.

Item Type: Thesis (Doctoral)
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Subjects: Q Science > QC Physics > QC0501 Electricity and magnetism > QC0522 Electricity > QC0680 Quantum electrodynamics
Depositing User: Library Cataloguing
Date Deposited: 30 Sep 2013 11:07
Last Modified: 17 Sep 2015 11:49
URI: http://sro.sussex.ac.uk/id/eprint/46447

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