On the photon vector potential Original Research Article

A method of calculating the expression for the single-photon classic vector potential is proposed. The calculation is performed within the model framework of a non-relativistic one-dimensional harmonic oscillator interacting with a quantized electromagnetic field and with the field of a single external photon. The calculated vector potential of the single photon, i.e. the single-photon wave packet, complies with dʹAlembertʹs equation to the accuracy of the calculations performed in the paper. In a system of coordinates that moves together with the photon with the velocity of light in vacuum, the expression for that wave packet is independent of time. The integral of the energy density calculated with the help of the single-photon vector potential as taken over the volume throughout the space is equal to the photon energy quantum, i.e. the integral is finite and does not depend on time.