Inversion asymmetry of photoelectron angular distributions in circularly polarized short pulses

The interaction of circularly polarized pulses with atoms is studied in the frame of nonperturbative scattering theory, and the photoelectron angular distributions (PADs) of atoms ionized in various pulse-lengths are obtained. Our study shows that, due to multichannel transitions, the PADs in circularly polarized short pulses are not isotropically, and the ejected electrons are not equal in the opposite directions. The optimal emission is related to the initial phase of the ultrashort pulses, which makes it possible to control the motion of the ejected electrons by the initial phase of pulses.