Spin in Compton scattering with pronounced polarization dynamics

Abstract

We theoretically investigate a scattering configuration in Compton scattering, in which the orientation of the electron spin is reversed and simultaneously, the photon polarization changes from linear polarization into circular polarization. The intrinsic angular momentum of electron and photon are computed along the coincident propagation direction of the incoming and outgoing photon. We find that this intrinsic angular momentum is not conserved in the considered scattering process. We also discuss the generation of entanglement for the considered scattering setup and present an angle dependent investigation of the corresponding differential cross section, Stokes parameters and spin expectation.Comment: 15 pages, 13 figure

Spin-dependent two-photon Bragg scattering in the Kapitza-Dirac effect

“…The Compton tensor (5) is known in quantum field theory literature [70,72] and describes the spin and polarization dependent scattering amplitude in Compton scattering. Note, that the results in our previous work [68] were mistakenly based on a Compton tensor expression for linear photon polarizations from reference [75], where the outgoing pho- ton polarization (r) * k…”

“…In this article we discuss spin-dependent Kapitza-Dirac diffraction with a two photon interaction which takes place in a Bragg scattering scenario. The approach is inspired by a previous work of one of us, which is investigating spin properties in Compton scattering [68]. While in Compton scattering an incoming electron and incoming photon scatter off into an outgoing electron and outgoing photon, one could replace the incoming and outgoing photons by classical electro-magnetic fields of strong laser beams and consider the electron quantum dynamics in terms of the Furry picture [69][70][71].…”

“…Therefore, the situation for a spin interaction of an electron with a photon in Compton scattering can be identified with a spin-dependent laser-electron interaction. The inspiration for the interacting setup which we take from reference [68] is the possibility for two-photon spin-dependent Bragg scattering, which can be achieved by forming a standing light wave from two counterpropagating laser beams, of which one is linearly polarized and the other is circularly polarized. We then predict the existence of a spin-dependent diffraction effect, if a beam of electrons crosses the standing light wave with a momentum of about 1mc along the polarization direction of the linearly polarized laser beam, where m is the electron restmass and c the vacuum speed of light.…”

“…This outlines the content of the paper where the article is structured in the following way: Section II discusses the identification of Compton scattering with the process of two-photon electron diffraction in a standing light wave. From this, we take the parameters for the electron and for the photon as in the setup in reference [68] and transfer it to a relativistic quantum simulation which is exhibiting spin-dependent electron diffraction in section III. After having demonstrated the possibility of this type of twophoton spin-dependent electron diffraction in the Bragg regime, we consider the possibility of an experimental implementation of the effect at the Shanghai High Repetition Rate XFEL and Extreme Light Facility (SHINE) in section IV.…”

Linear Rayleigh and Raman scattering to the second order: Analytical results for light scattering by any scatterer of size k0d≲1/10

“…Theoretical understanding of light scattering is sufficiently advanced to enable determinations of the nature of interstellar dust [3], radar [4], studies of the structures of viruses [5] and the measurement of the salinity of seawater [6], to name but a few applications. There is much still to be explored, however, and the study of light scattering remains at the cutting edge of research [7][8][9][10][11][12][13][14][15].…”