title: Unidirectional electronic ring current driven by a few cycle circularly polarized laser pulse: quantum model simulations for Mg-porphyrin.
abstract: A circularly polarized ultraviolet (UV) laser pulse may excite a unidirectional valence-type electronic ring current in an oriented molecule, within the pulse duration of a few femtoseconds (e.g., tau = 3.5 fs). The mechanism is demonstrated by quantum model simulation for |X = |1(1)A(1g) --> |E(+) = |4 (1)E(u+) population transfer in the model system, Mg-porphyrin. The net ring current generated by the laser pulse (I = 84.5 microA) is at least 100 times stronger than any ring current, which could be induced by means of permanent magnetic fields, with present technology.
authors.affiliation: Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Barth
authors.forename: Jörn
authors.initials: J
authors.lastname: Manz
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Shigeta
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Yagi