Competition between instanton and non-instanton tunneling in multidimensional systems
Kin’ya Takahashi, Kyushu Institute of Technology
There are two types of tunneling mechanisms working for mutli-dimensional barrier tunneling. One is well known instanton which induces barrier penetration. The other is non-instanton tunneling, in which tunneling particles go over a barrier top. It is explained by multiphoton assisted tunneling, while from the semiclassical view point it is interpreted by ’Stable-unstable manifold guided tunneling, say SUMGT as an abbreviation.In this talk, we investigate instanton type tunneling and non-instanton tunneling from the view points of quantum and semiclassical dynamics.Taking periodically perturbed step potential and barriers as models, we give the interpretation between quantum and semiclassical explanations of non-instanton tunneling and we discuss the problem: How do the transitions between instanton and non-instanton tunneling occur with change of the perturbation frequency? Further taking a periodically perturbed resonance potential, we consider the problem: How does the resonance affect the properties of instant type tunneling and non-instanton tunneling?