We exhibit long-lived resonances in scattering from two-dimensional soft cage potentials comprised
of three and four Gaussian peaks. Specific low-energy resonances with very narrow width
are shown to correspond to classical multiple-reflection events. These states have much larger
probability densities inside the cage than outside and mimic bound states in the sense that the
symmetry-breaking effect of the incident wave is relatively small. As a result we have found that
isolated states display the simple symmetry characteristics of bound states. Overlapping resonances
exhibit a mixing of symmetry classes leading to wave functions of lower symmetry, like those of
wider resonances at higher energy. We demonstrate that at energies below the lowest resonances of
two-dimensional cages, where the distance across the entrance of the cage corresponds to less than
half a wavelength, the wave function may still gain access to the interior region by squeezing its
wavelength in the necessary direction at the expense of the kinetic energy in the direction normal
to the opening. The resulting curvature of the wave function in the donor dimension corresponds
to an imaginary wavenumber, curving away from the plane defined by zero amplitude. This mechanism
for passing between obstacles may be relevant for electronic and optical devices having spatial
structures with dimensions comparable to the wavelengths of the energy carriers. / Graduation date: 2005
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/29080 |
| Date | 09 December 2004 |
| Creators | Rowe, Kirk, 1966- |
| Contributors | Siemens, Philip J. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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