Experimental investigation on Non-local entanglement in electron-exchange collisions

Abstract

The main goal of this experiment is to investigate quantum entanglement between massive particles with the potential for transferring spin polarization via non-local quantum effects. This approach employs electron-exchange scattering with spin-1/2 targets to generate entanglement. By eliminating photon-mediated interactions, this experimental configuration enables direct examination of non-local quantum state transfer between massive particles, whether temporally immediate or subluminal, while providing fundamental insights into entangled quantum systems comprising two massive particles. The experiment consists of two primary phases. Initially, elastic electron-exchange scattering between free, unpolarized electrons and unpolarized fermionic atoms (sodium) is experimentally achieved to create a tunable entanglement resource. After the collision, the electrons will scatter and calculations show that the maximum degree of entanglement between sodium atoms and electrons occurs when the energy of incoming electrons is 10 eV and they are scattered at 60 degrees angle. Subsequently, after a well-defined delay period that allows electrons to travel away from the collision center, a nanosecond-pulse laser with circularly polarized light (σ+) is used to excite the sodium atoms. This, in part, transfers the light’s polarization to the entangled atoms. Due to quantum entanglement, these entangled atoms are then predicted to transmit their polarization (or a part of it) to the previously unpolarized, though entangled, electronic ensemble. The key element here is the transfer of polarization from the sodium atoms to the entangled free electrons, even when they are separated by meters. Finally, the spin polarization of the electron ensemble is detected using a Mott polarimeter, where a non-zero measurement would indicate non-local quantum mechanical effects. Preliminary experimental results align partially with theoretical predictions, suggesting the potential validity of the proposed approach. However, further investigations are needed to fully confirm these findings and establish conclusive evidence of the observed quantum mechanical effects.