title: Quantum unidirectional rotation directly imaged with molecules.
abstract: A gas-phase molecular ensemble coherently excited to have an oriented rotational angular momentum has recently emerged as an appropriate microscopic system to illustrate quantum mechanical behavior directly linked to classical rotational motion, which has a definite direction. To realize an intuitive visualization of such a unidirectional molecular rotation, we report high-resolution direct imaging of direction-controlled rotational wave packets in nitrogen molecules. The rotational direction was regulated by a pair of time-delayed, polarization-skewed laser pulses, introducing the dynamic chirality to the system. The subsequent spatiotemporal propagation was tracked by a newly developed Coulomb explosion imaging setup. From the observed molecular movie, time-dependent detailed nodal structures, instantaneous alignment, angular dispersion, and fractional revivals of the wave packet are fully characterized while the ensemble keeps rotating in one direction. The present approach, providing an accurate view on unidirectional rotation in quantum regime, will guide more sophisticated molecular manipulations by utilizing its capability in capturing highly structured spatiotemporal evolution of molecular wave packets.
authors.affiliation: Institute for Molecular Science, National Institutes of Natural Sciences and SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Mizuse
authors.affiliation: Department of Physics and Mathematics, Aoyama Gakuin University, Sagamihara, Kanagawa 252-5258, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Kitano
authors.affiliation: Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hasegawa
authors.affiliation: Institute for Molecular Science, National Institutes of Natural Sciences and SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan. ; Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, Tokyo 152-8550, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ohshima
keywords: coherent control; ion imaging; molecular rotational wave packet; unidirectional molecular rotation