Macroscopic and mesoscopic matter waves
  It has been shown earlier that matter waves which are known to lie typically in the range of a few Angstrom, can also manifest in the macrodomain with a wave length of a few centimeters, for electrons propagating along a magnetic field. This followed from the predictions of a probability amplitude theory by the author in the classical macrodomain of the dynamics of charged particles in a magnetic field. It is shown in this paper that this case constitutes only a special case of a generic situation whereby composite systems such as atoms and molecules in their highly excited internal states,can exhibit matter wave manifestation in macro and mesodomains. The wave length of these waves is determined, not by the mass of the particle as in the case of the de Broglie wave, but by the frequency, associated with the internal state of excitation, and is given by a nonquantal expression, $\lambda =2\pi v/\omega$, $v$ being the velocity of the particle. For the electrons in a magnetic field the frequency corresponds to the gyrofrequency, $\Omega$ and the nonquantal wave length is given by $\lambda = 2\pi v_{\parallel}/\Omega$; $v_{\parallel}$ being the velocity of electrons along the magnetic field. 
Ram K. Varma