ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
We study the excitation of molecular rotation by microwave pulses of duration σ which occur periodically with frequency ω. We analyze the molecular dynamics both classically and quantum mechanically and consider situations where the coupling of the field to the molecule is strong. In both approaches, the angular momentum transmitted to the molecule is confined to a finite band of width ≈1/σ. But, while the classical dynamics displays chaotic features, the quantum treatment distinguishes clearly between two regimes. Resonance excitation occurs when ω is rationally related to the basic rotation frequency ω0. Off resonance (ω/ω0 irrational), the probability to transfer angular momentum to the molecule is small and the underlying mechanism for this effect is analogous to the Anderson model of localization in a one-dimensional random lattice with a finite number of sites. We show that the conditions required by our analysis can be achieved with, e.g., PbTe or CsI molecules and conventional field strengths and we propose this system as an experimental testing ground for the Anderson localization mechanism.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.450330
