title: Displacing Rydberg electrons: the mono-cycle nature of half-cycle pulses.
abstract: A THz "half-cycle" pulse is a fast ( <1 ps) unipolar pulse, followed by a slow unipolar pulse of opposite polarity. We found that the interaction of such THz pulses with very high Rydberg states results in a displacement of the electron within the atom, while the ionization is strongly suppressed. In classical terms: the first fast unipolar feature corresponds to a start kick of the Rydberg electron, while the second unipolar feature acts as a stop kick. A semiclassical model is presented which qualitatively reproduces the ionization suppression and redistribution.
authors.affiliation: FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: Wesdorp
authors.forename: F
authors.initials: F
authors.lastname: Robicheaux
authors.forename: L D
authors.initials: LD
authors.lastname: Noordam