I would not agree with this. See my other post. I don't see the difficulty in assigning a range of frequencies to a photon, given the way the uncertainty principle applies to all such cases.
Uncertainty in momentum x position is not the same as uncertainty in frequency x position.
At best stating a photon has frequency appears an unprovable mathematical assumption/analogue, not a physical one, especially when you include additional harmonics.
How would you go about detecting the harmonics and base frequency of a "single" photon, if it had any? I do not think you can. All you can detect is the energy and momentum, and polarisation of the photon, nothing more. To ascribe different colours, different frequencies appears wrong, they can only be regarded as packets of energy. E=pc might mathematically give the same result as E=hf.
A photon has no charge or magnetic field, it only has inertial energy, the only way this energy level can fluctuate is if it interacts with perhaps virtual particles, Compton scattering for example, or is absorbed and remitted by some other substance. There is no need to ascribe a photon a frequency, an energy level is sufficient relating to its momentum.
To assign frequencies to photons radio waves are used. A radio wave has frequency, which may consist of a wave of photons, some of which are absorbed by receivers. A radio wave is not a single photon, unless the definition of a photon has changed.
Virtual particles separated momentarily via a moving magnetic field around the transmitter likely acquire enough energy to produce photons on their decay, which radiate as a radio wave consisting of electromagnetically neutral photons, that only have momentum to transfer on the receiving end.
A little bit of speculation is involved here, but I do not think an individual photon can be ascribed any other properties than E=pc
Edited by Flummoxed, 02 May 2019 - 10:54 AM.