Research Institute for Electronic Science, Hokkaido University


LAST UPDATE 2017/08/04

  • 研究者氏名
    Researcher Name

    寺本央 Hiroshi TERAMOTO
    准教授 Associate Professor
  • 所属
    Professional Affiliation

    Research Institute for Electronic Science, Hokkaido University

    Molecule & Life Nonlinear Sciences Laboratory
  • 研究キーワード
    Research Keywords

    Applied Singularity Theory
    chemical reaction dynamics, mode selectivity
    Non-adiabatic dynamics
    Lie canonical perturbation theory
Research Subject
Understandings of chemical reaction dynamics in terms of dynamical systems theory

研究の背景 Background


To understand molecular reactions in terms of dynamical systems theory is one of the central issues in chemical reaction dynamics since 1914 when Marcelin represented reactions by the motion of points in the phase space. For example, selective excitation of a specific molecular vibrational mode and realization of a selective reaction in terms of it cannot be achieved only by the conventional thermal and statistical points of view but requires dynamical systems viewpoints. Despite its importance in application, its understandings and controls are limited to a few atomic molecular systems and methods applicable to more complicated systems are highly demanded.

研究の目標 Outcome


We have improved the standard canonical perturbation theory to identify a bottleneck of energy transfers among molecular vibrational modes, developed a non-perturbative method to construct cylindrical manifolds that make it possible to understand roaming reactions, which cannot be understood in terms of intrinsic reaction coordinates, constructed a method to construct a cylindrical manifold that is applicable to systems with a few hundred degrees of freedom. The aim of this research is to establish versatile mathematical techniques to uncover the origin of reaction selectivity at the first principle.

研究図Research Figure

Fig.1. Cylindrical manifolds of the Stark saddle in a hydrogen atom in crossed electric and magnetic fields in a three dimensional coordinate space. The proton is indicated by the violet circle. Every ionizing electron runs through the red cylinder and then the green cylinder to escape from the proton. Fig.2. Stationary Lagrangian Coherent Structure calculated in ABC flow (a) forward in time, (b) backward in time. Tracer particles cannot cross these structures and thus they provide impenetrable barrier for the transportation and mixing of the tracer particles. Fig.3. Schematic figure to illustrate the issue in the conventional perturbation theory. Our new method made it possible to overcome the issue.

文献 / Publications

J. Math. Phys. 58, 073502 (2017), Nonlinearity 28, 2677 (2015), Phys. Rev. Lett. 115, 093003 (2015), Theor. Chem. Acc. 133, 1571 (2014), J. Chem. Phys. 141, 104907 (2014), Chaos 23, 043107 (2013), Phys. Rev. Lett. 106, 054101 (2011), J. Chem. Phys. 129, 094302 (2008).