Phase-sensitive experiments, geometrical

We hope that the studies summarized above will motivate time-resolved interference experiments on Jahn-Teller systems. Half-odd quantum numbers for molecular pseudorotation have been reported in the continuous wave spectra of Na, [47], benzene [48] and sym-triazine [44]. The half-odd quantum numbers are strong evidence for the presence of geometric phase factors. Benzene and sym-triazine have nondegenerate ground states and would therefore be the most obvious choices for phase sensitive measurements of the kind we propose. The 3s E Rydberg state of 5ym-triazine has the simplifying feature of exhibiting Jahn-Teller... 

Infrared spectroscopy of adsorbed CO is a useful characterization tool for dendrimer-templated supported nanoparticles, because it directly probes particle surface features. In these experiments, which are performed in a standard infrared spectrometer using an in-situ transmission or DRIFTS cell, a sample of supported DENs is first treated to remove the organic dendrimer. Samples are often reduced under H2 at elevated temperature, flushed with He, and cooled to room temperature. Dosing with CO followed by flushing to remove the gas-phase CO allows for the spectrum of surface-bound CO to be collected and evaluated. Because adsorbed CO stretching frequencies are sensitive to surface geometric and electronic effects, it is potentially possible to evaluate the relative effects of each on nanoparticle properties. 

The model Hamiltonian of Section II captures some of the essential features of the electronic and vibrational structure of polyatomic molecules, like benzene and 5ym-triazine, that have both nondegenerate and degenerate, Jahn-Teller active, electronic levels. In this section interference experiments are described which will be sensitive to the geometric phase development accompanying adiabatic nuclear motion on either of the electronic potential energy surfaces in the Jahn-Teller pair. 

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