Circular dichroism in photoemission from oriented molecules at surfaces
Abstract
Measurements of a new observable quantity in photoemission from oriented molecules are reported. Using circularly polarized radiation, the photoemission intensities for a special geometry were found to depend on photon helicity. The basic theoretical description of the effect is outlined, showing that it occurs for all spatially fixed molecules in the electric dipole approximation and does not depend on electron-spin effects. Experimental case studies for diatomics (CO, NO), benzene, and the "heavy" molecule CH_3I, all oriented by adsorption on Pd(111) or graphite (0001), reveal huge intensity asymmetries in all cases. Comparisons of these measured asymmetries are also made with the results of model calculations based on oriented CO, NiCO, and NO. The effect provides a sensitive probe of molecular orientation and of photoemission dynamics.
Additional Information
© 1991 Elsevier Science Publishers B.V. Received 6 November 1990; accepted for publication 30 January 1991. Available online 19 September 2002. Contribution Number 8033. The authors thank G. Raseev (Orsay) for useful discussions and correspondence. N.A.C. acknowledges the hospitality of the Laboratoire de Photophysique Moleculaire, Université de Paris-Sud, extended to him during the work on this paper, and the financial support of the Centre National de la Recherche Scientifique. The excellent cooperation of the staff of BESSY is gratefully acknowledged. R.L.D. gratefully acknowledges support under a National Research Council Resident Research Associateship. Work at the University of Bielefeld was supported by BMFT (05 331 AXI). Work at the California Institute of Technology was supported by the Air Force Office of Scientific Research through Grant No. AFOSR-89-0132 and the National Science Foundation (CHE-8521391). We also acknowledge the use of resources of the San Diego Supercomputer Center which is supported by the National Science Foundation.Additional details
- Eprint ID
- 62165
- DOI
- 10.1016/0039-6028(91)90593-H
- Resolver ID
- CaltechAUTHORS:20151117-122643342
- Centre National de la Recherche Scientifique (CNRS)
- National Research Council Resident Research Associateship
- 05 331 AXI
- BMFT
- AFOSR-89-0132
- Air Force Office of Scientific Research (AFOSR)
- CHE-8521391
- NSF
- NSF
- Created
-
2015-11-17Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Other Numbering System Name
- Caltech Arthur Amos Noyes Laboratory of Chemical Physics
- Other Numbering System Identifier
- 8033