Planck-Einstein’s and de Broglie’s are two fundamental equations of quantum physics. But vacuum Cherenkov radiation (VCR) is convincing evidence that the momentum of a single photon should be where the phase constant takes the place of the wave vector . Apart from the momentum, the operator is associated to . The acousto-optic effect and anomalous VCR can be applied to test this conjecture.
International Letters of Chemistry, Physics and Astronomy (Volume 50)
Z. Y. Wang "Extension to de Broglie Formula of Quantum Mechanics", International Letters of Chemistry, Physics and Astronomy, Vol. 50, pp. 50-60, 2015