Wave-packet reduction during particle-coordinate measurement

正也 矢部

Michele Cini, M. De Maria, Gabriel Mattioli +1 more

Alexandr Petrovich Davydov, Tatiana Pavlovna Zlydneva

The main principles of photon quantum mechanics describing its single-particle states by means of the wave function (wave packet) in the coordinate representation are given. The results of modeling of the propagation in space-time of wave packet with a Gaussian distribution of the momentum of a photon corresponding to femtosecond laser radiation are discussed. On the basis of the general ideas about the evolution of this packet and within the framework of constructed photon quantum mechanics, the quantum-mechanical explanation of the experimentally registered (previously) reduction of speed of the free photons, “structured” in the same way as the light in Bessel and Gaussian beams, is proposed. It is emphasized that in fact the photon is not a some formed quantum corpuscle, but it is a quasi-particle, which is the result of propagation of spin wave in physical vacuum, the nature of which should be considered at the Planck distances simultaneously with structure of fundamental particles.

E. Constant, Henrik Stapelfeldt, P. B. Corkum

S. Machida, Mikio Namiki

New theory of measurement is presented to show that quantum mechanics can describe the whole processes of quantum-mechanical measurement leading to the so-called reduction of wave packet if applied properly to the total system of object and apparatus. We introduce a simple model, where momenta of particles are measured using a perfect rigid mirror, to yield the reduction of wave packet in a clear-cut way. Microscopic uncertainties of macroscopic quantities and the dynamical scattering theory play the essential roles. Before entering into the main part, we briefly summarize the controversial points in the theory of measurement.