title: Dynamic stark control of torsional motion by a pair of laser pulses.
abstract: The torsional motion of a molecule composed of two substituted benzene rings, linked by a single bond, is coherently controlled by a pair of strong (3×10^{13}  W cm^{-2}), nonresonant (800 nm) 200-fs-long laser pulses-both linearly polarized perpendicular to the single-bond axis. If the second pulse is sent at the time when the two benzene rings rotate toward (away from) each other the amplitude of the torsion is strongly enhanced (reduced). The torsional motion persists for more than 150 ps corresponding to approximately 120 torsional oscillations. Our calculations show that the key to control is the strong transient modification of the natural torsional potential by the laser-induced dynamic Stark effect.
authors.affiliation: Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark.
authors.forename: Lauge
authors.initials: L
authors.lastname: Christensen
authors.affiliation: Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark.
authors.forename: Jens H
authors.initials: JH
authors.lastname: Nielsen
authors.affiliation: Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark.
authors.forename: Christian B
authors.initials: CB
authors.lastname: Brandt
authors.affiliation: Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark.
authors.forename: Christian B
authors.initials: CB
authors.lastname: Madsen
authors.affiliation: Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark.
authors.forename: Lars Bojer
authors.initials: LB
authors.lastname: Madsen
authors.affiliation: Department of Chemistry, University of Oxford, the Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, United Kingdom.
authors.forename: Craig S
authors.initials: CS
authors.lastname: Slater
authors.affiliation: Department of Chemistry, University of Oxford, the Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, United Kingdom.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Lauer
authors.affiliation: Department of Chemistry, University of Oxford, the Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, United Kingdom.
authors.forename: Mark
authors.initials: M
authors.lastname: Brouard
authors.affiliation: Department of Chemistry, Laboratory for Instruction in Swedish, University of Helsinki, A.I. Virtanens Plats 1, P.O. Box 55, FI-00014 Helsinki, Finland.
authors.forename: Mikael P
authors.initials: MP
authors.lastname: Johansson
authors.affiliation: Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Shepperson
authors.affiliation: Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Stapelfeldt