Time Delay Statistics of Photoelectric Emissions: An Experimental Test of Classical Radiation Theory

Abstract

For many years the photoelectric effect has been taken to provide evidence for the quantum nature of electromagnetic radiation. However, as has been pointed out from time to time[1–3], if the electromagnetic field is treated as a classical, c-number perturbation acting on the bound electron, essentially the same conclusions can be reached as by quantum electrodynamics. For example, photoemission takes place only when the frequency ω is high enough for ℏω to exceed the work function W of the electrons,

$$\hbar {\rm{\omega }} > {\rm{W,}}$$

(1)

and the probability of photoemission at time t is proportional to the expectation value of the light intensity I(t) at time t,

$$_{{\text{at time t within }}\Delta {\text{t}} = {\text{constant x < I(t) > }}\Delta {\text{t}}{\text{.}}}^{{\text{photoemission probability}}}$$

(2)

This work was supported by the National Science Foundation and by the Air Force Office of Scientific Research.