Fig. 1. Photoelectron momentum distributions in the polarization plane for ionization of hydrogen by right–left circularly polarized attosecond pulses with the ellipitcity (a) η1=1, η2=−1, (b) η1=0.75,η2=−0.75, (c) η1=0.5, η2=−0.5, (d) η1=0.25, η2=−0.25, (e) η1=0, η2=0, which are delayed in time by 2478 as.

Fig. 2. Photoelectron momentum distributions in the polarization plane for ionization of H by right–left circularly polarized attosecond pulses with the ellipitcity (a) η1=1, η2=−1, (b) η1=1, η2=−0.5, (c) η1=0.5, η2=−0.5, (d) η1=0.25, η2=−0.25, (e) η1=0.25, η2=−0.25, which are delayed in time by 2478 as.

Fig. 3. Photoelectron momentum distributions in the polarization plane for ionization of H by right–right circularly polarized attosecond pulses with the ellipitcity (a) η1=η2=1, (b) η1=η2=0.5, (c) η1=0.5, η2=0.25, (d) η1=η2=0.25, which are delayed in time by 2478 as.

Fig. 4. Photoelectron momentum distributions in the polarization plane for ionization of H by a linearly polarized attosecond pulse and a circularly polarized attosecond pulse with the ellipitcity (a) η1=0.5, and (b) η1=1, which are delayed in time by 2478 as.

Fig. 5. Photoelectron momentum distributions in the polarization plane for ionization of H by a right–left elliptically polarized attosecond pulse with the ellipitcity (a)–(c) η1=0.5, η2=−0.5, and (d)–(f) η1=1, η2=−1, delayed in time by (a) and (d) 826 as, (b) and (e) 1652 as, and (c) and (f) 2478 as.