title: Sub-cycle strong-field interferometry.
abstract: A nonlinear interferometry scheme is described theoretically to induce and resolve electron wavefunction beating on time scales shorter than the optical cycle of the time-delayed pump and probe pulses. By employing two moderately intense few-cycle laser fields with a stable carrier-envelope phase, a large range of the entire electronic level structure of a quantum system can be retrieved. In contrast to single-photon excitation schemes, the retrieved electronic states include levels that are both dipole- and non-dipole-accessible from the ground electronic state. The results show that strong-field interferometry can reveal both high-resolution and broad-band spectral information at the same time with important consequences for quantum-beat spectroscopy on attosecond time scales.
authors.affiliation: Max-Planck Institut f¨ur Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Ott
authors.forename: Philipp
authors.initials: P
authors.lastname: Raith
authors.forename: Thomas
authors.initials: T
authors.lastname: Pfeifer