New Spin-Polarized Electron Source Based on Alkali Antimonide Photocathode

New spin-dependent photoemission properties of alkali antimonide semiconductor cathodes are predicted based on the detected optical spin orientation effect and DFT band structure calculations. Using these results, the Na2KSb/Cs3Sb heterostructure is designed as a spin-polarized electron source in combination with the Al0.11Ga0.89As target as a spin detector with spatial resolution. In the Na2KSb/Cs3Sb photocathode, spin-dependent photoemission properties were established through detection of a high degree of photoluminescence polarization and high polarization of the photoemitted electrons. It was found that the multi-alkali photocathode can provide electron beams with emittance very close to the limits imposed by the electron thermal energy. The vacuum tablet-type sources of spin-polarized electrons have been proposed for accelerators, which can exclude the construction of the photocathode growth chambers for photoinjectors.

Automated summary

New spin-dependent photoemission properties of alkali antimonide semiconductor cathodes are predicted based on optical spin orientation effect and DFT band structure calculations. A Na2KSb/Cs3Sb heterostructure is designed as a spin-polarized electron source, combined with an Al0.11Ga0.89As target as a spin detector with spatial resolution. The photoluminescence polarization and high polarization of the photoemitted electrons confirm the spin-dependent photoemission properties of the Na2KSb/Cs3Sb photocathode. It is found that the multi-alkali photocathode can provide highly collimated electron beams close to the electron thermal energy limit. Vacuum tablet-type sources of spin-polarized electrons are proposed for accelerators, eliminating the need for photocathode growth chambers in photoinjectors.