Frustrated tunneling ionization in strong circularly polarized two-color laser fields

We study the frustrated tunneling ionization (FTI) in counter-rotating and co-rotating circularly polarized two-color (CPTC) laser fields using a classical electron ensemble method. We find that the FTI probability depends sensitively on the relative helicity and the field amplitude ratio of the two-color laser fields. The FTI probability in the counter-rotating CPTC laser fields is three orders higher than that in the co-rotating fields. In the counter-rotating CPTC laser fields, the maximal FTI probability appears at the field amplitude ratio of ∼2.0, while in the co-rotating CPTC laser fields it appears at the ratio of ∼3.6. Tracing the electron trajectories, we find that recollision-assisted recapture plays an important role for the FTI in the CPTC laser fields. We further show that the angular momentum of the Rydberg state from the FTI events can be controlled by changing the field amplitude ratio of the counter-rotating CPTC laser fields, while it is nearly unchanged in the co-rotating CPTC laser fields.