Excitation of atoms by bicircular laser pulses*

We study the excitation of Rydberg states for the interaction of atoms with intense bi-circular laser pulses using numerical solutions of the time-dependent Schr\"{o}dinger equation. By identifying the pathways in co-rotating and counter-rotating bi-circular laser pulses, we interpret an enhancement in excitation for the counter-rotating case consistent with the experimental results in Ref. [1]. We further identify several other features, e.g. angular momentum selection rules for the populations in the excited states and a cut-off in angular momentum that is a dependent on the frequency and intensity of the two circular laser pulses. [1] C. A. Mancuso, et al., PRA 96, 023402 (2017)