title: Resolving subcycle electron emission in strong-field sequential double ionization.
abstract: Using a fully classical model, we have studied sequential double ionization (SDI) of argon driven by elliptically polarized laser pulses at intensities well in the over-barrier ionization region. The results show that ion momentum distributions evolve from the two-band structure to the four-band, six-band structure and finally to the previously obtained four-band structure as the pulse duration increases. Our analysis shows that the evolution of these band structures originates from the pulse-duration-dependent multiple ionization bursts of the second electron. These band structures unambiguously indicate the subcycle electron emission in SDI.
authors.forename: Aihong
authors.initials: A
authors.lastname: Tong
authors.forename: Yueming
authors.initials: Y
authors.lastname: Zhou
authors.forename: Peixiang
authors.initials: P
authors.lastname: Lu