Quantum Theory of Induced Multiphoton Cherenkov Process

Abstract

The existence of critical intensity in the induced Cherenkov process at which nonlinear resonance with a given coherent radiation field takes place leading to threshold phenomena of particle “reflection” and capture, in the quantum description, corresponds to multiphoton absorption/radiation of the particle at free–free transitions. Hence, first it is important to determine the probabilities of induced Cherenkov radiation and absorption below the critical value and close to this one when these probabilities considerably increase. As a result of the multiphoton absorption/radiation the particle quantum state is modulated at the wave harmonics. Then, one should elucidate the role of particle spin in these phenomena since in dielectriclike media the wave periodic electromagnetic field in the intrinsic frame of reference becomes a static magnetic field and spin interaction with such a field should resemble the Zeeman effect. What other quantum effects may be expected in induced Cherenkov process taking into account that spontaneous Cherenkov effect is of classical nature and has no quantum peculiarity? The particle “reflection” effect from the wave envelope is also of classical nature, but the quantum state of the reflected particle after the interaction becomes modulated at X-ray frequencies. The classical phenomenon of particle capture by the wave leads to quantum effect of zone structure of particle states like the particle states in a crystal lattice. The inelastic diffraction scattering of the particles on the traveling EM wave of intensity below the critical value in induced Cherenkov process takes place like Bragg diffraction (elastic) on a crystal lattice. The consideration of these quantum problems is the subject of this chapter.