Observation of quantum confinement and quantum size effects



Recently, the change in optical properties of ultra-thin silicon on insulator films was shown to be due to quantum confinement. The E1 critical point shifted to higher energies with a 1/L2 dependence, and the shift was observed room temperature. Yet, quantum confinement effects in thin metal have yet to be observed optically. This leads to a number of questions that we raise and for which we provide preliminary answers. Shifts less than kT in energy can be observed optically when the final state is spatially and temporally localized. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)