Entanglement manifestation in spin resolved electron–electron scattering.

The polarization vector P of scattered electrons interacting with a polarized target electrons is compared with the entanglement (or non-separability) of the electron states of the interacting electron pair. The separability S is defined as a linear function of the von Neumann entropy. The shapes of the functions P ( θ , Ω , φ ) and S ( θ , Ω , φ ) are similar and simultaneously achieve their maximum value at the scattering angle θ values close to 0 and π and simultaneously tend to zero in the case of symmetric scattering at θ ≈ π /2. In the latter case the scattered electrons are described by an asymmetric spin part of the wave function, which by definition corresponds to the spin entangled ( S ≈ 0) electron states of the interacting electron pair. Comparison of the model calculation results with experimental results of the spin polarized electron spectroscopy of the ferromagnetic solid shows qualitative agreement. The analytical expression relating polarization and separability of the two interacting particles enables use the measured polarization of scattered electrons for estimation of the spin-entanglement or separability of the two particle systems. [ABSTRACT FROM AUTHOR]