Threshold Phenomena in Nonlinear Currents Upon Metallization of Si(001)
Abstract
Using a novel combination of fundamental and harmonic polarizations, we have used optical second harmonic (SH) generation to probe the nonlinear currents induced parallel to the surface plane of a Si(001) crystal upon adsorption of Na, K, and Cs. For all three alkalis, we observed abrupt thresholds in SH intensity and relative SH phase shift at the same coverage of very nearly one-sixth of a monolayer. We speculate that these thresholds correspond to insulator-metal transitions, and that a recently-observed low-coverage (2x3) structure is a Mott-Hubbard-like insulator.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 26, 1992
- Accession Number
- ADA252255
Entities
People
- Geraldine L. Richmond
- S. Arekat
- Stephen Douglas Kevan
Organizations
- University of Oregon