Coverage-dependent quantum versus classical scattering of thermal neon atoms from Li/Cu(100).
We show that subtle variations in surface structure can enhance quantum scattering and quench atom-surface energy transfer. The scattering of thermal energy neon atoms from a lithium overlayer on a copper substrate switches between a classical regime, dominated by multiphonon interactions, and a quantum regime, dominated by elastic diffraction. The transition is achieved by simple tailoring of the lithium coverage and quantum scattering dominates only in the narrow coverage range of theta=0.3-0.6 ML. The results are described qualitatively using a modified Debye-Waller model that incorporates an approximate quantum treatment of the adsorbate-substrate vibration.
Maclaren
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Cavendish Laboratory, University of Cambridge, J. J. Thompson Avenue, Cambridge CB3 0HE, United Kingdom. dmaclaren@physics.org
Huang
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Levi
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Allison
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