LOCALIZATION OF MULTIPHOTON IONIZATION/DISSOCIATION RESONANCE WAVE FUNCTIONS IN AC FIELDS

摘要

Although it has been proved before [J. Chem. Phys. 101, 9716 (1995)] that the complex scaled photoionizing/photodissociating resonances are associated with square integrable functions (only when the time-dependent Hamiltonian is represented in the velocity or acceleration gauges), it is proved here that in the length gauge a narrow resonance wave function (and not a broad one!) may diverge exponentially at some period of time but yet decays exponentially in space at some other time. When the exterior scaling method is used and the coordinate is rotated into the complex plane by an angle less than 180 degrees the resonance quasi-energy state (in the length gauge) decays to zero, like a bound state, at any given time. The localization of the resonance quasi-energy (Floquet) states in the length guage as the laser frequency vanishes (i.e., when the field is varied slowly and can be considered as de field) is proven and found to be consistent with Herbst and Simon's proof [Commun. Math. Phys. 64, 279 (1978); Ibid, 80, 181 (1981)] for atoms in de Stark fields. (C) 1997 John Wiley & Sons, Inc. [References: 32]