A physically motivated quantization of the electromagnetic field

Bennett, R. , Barlow, T. M. and Beige, A. (2016) A physically motivated quantization of the electromagnetic field. European Journal of Physics, 37(1), 014001. (doi: 10.1088/0143-0807/37/1/014001)

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The notion that the electromagnetic field is quantized is usually inferred from observations such as the photoelectric effect and the black-body spectrum. However accounts of the quantization of this field are usually mathematically motivated and begin by introducing a vector potential, followed by the imposition of a gauge that allows the manipulation of the solutions of Maxwell's equations into a form that is amenable for the machinery of canonical quantization. By contrast, here we quantize the electromagnetic field in a less mathematically and more physically motivated way. Starting from a direct description of what one sees in experiments, we show that the usual expressions of the electric and magnetic field observables follow from Heisenberg's equation of motion. In our treatment, there is no need to invoke the vector potential in a specific gauge and we avoid the commonly used notion of a fictitious cavity that applies boundary conditions to the field.

Item Type:Articles
Additional Information:TB acknowledges financial support from a White Rose Studentship Network on Optimising Quantum Processes and Quantum Devices for future Digital Economy. RB thanks the UK Engineering and Physical Sciences Research Council for an EPSRC Doctoral Prize.
Glasgow Author(s) Enlighten ID:Bennett, Dr Robert
Authors: Bennett, R., Barlow, T. M., and Beige, A.
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:European Journal of Physics
Publisher:IOP Publishing
ISSN (Online):1361-6404
Published Online:30 October 2015
Copyright Holders:Copyright © 2016 IOP Publishing Ltd
First Published:First published in European Journal of Physics 37(1): 014001
Publisher Policy:Reproduced under a Creative Commons License

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