Ma. Bouchene et al., Spin-polarized electrons produced by a sequence of two femtosecond pulses.Calculation of differential and global polarization rates, J PHYS B, 34(8), 2001, pp. 1497-1512
Citations number
35
Categorie Soggetti
Physics
Journal title
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
This paper presents a theoretical analysis of the possibilities of producin
g spin-polarized electrons with a sequence of two ultra-short time-delayed
laser pulses. The first pulse, which is right circularly polarized, excites
resonantly the fine structure np level of potassium atoms leading to a spi
n-flip and thus polarizing the atom. The second pulse ionizes the system th
ereby resulting in spin-polarized electron release. We examine and compare
several situations corresponding to different polarizations of the ionizing
pulse (sigma (+), sigma (-) and pi). For each case we derive analytical ex
pressions;for the angular and global electron spin-polarization rates as we
ll as for the differential cross sections. The obtained rates can be very h
igh (up to 100%) and can be controlled accurately on the femtosecond time s
cale by varying the time delay between the pulses.