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We report on the results of a joint experimental and numerical study on the sub-cycle laser field-driven electron dynamics that underlie the population of highly excited electronic states in multiply ionized argon dimers by electron recapture processes. Our experiments using few-cycle laser pulses with a known carrier-envelope phase (CEP) in combination with reaction microscopy reveal a distinct CEP-dependence of the electron emission and recapture process and, furthermore, a small but significant CEP-offset to the scenario in which no excited argon dimers are produced. With the help of classical ensemble trajectory simulations we trace down these different CEP-dependencies to subtle differences in the laser-driven sub-cycle electron trajectory dynamics that involve in both cases the transfer of an electron from one argon ion across the system boundary to the neighboring ion and its transient capture on this ion. [ABSTRACT FROM AUTHOR]

With a stereo above-threshold ionization (ATI) apparatus, we systematically investigate the carrier-envelope phase (CEP) dependence of the photoelectron kinetic energy spectra from high-order ATI of Xe atom subject to a strong few-cycle laser field. Our measurements reveal a prominent step structure and a maximum in the photoelectron kinetic energy dependence of the yield asymmetry. The observed structures can be well reproduced by the numerical solution of time-dependent Schrödinger equation (TDSE) and the improved strong field approximation (ISFA) theory. According to our analysis, the step structure can be ascribed to the interference of long and short orbits, while the maximum is closely related to the distinct kinetic energy distributions of photoelectrons which elastically scatter on the core at odd and even returns. Our work provides a more comprehensive understanding of the CEP effects on high energy photoelectron emissions in a few-cycle laser field. [ABSTRACT FROM AUTHOR]