title: The determination of an inhomogeneous linewidth for a strongly coupled adsorbate system.
abstract: We present a set of experiments that provide a complete mapping of coherent and incoherent vibrational relaxation times for a molecule on a metal surface, CO/Ir{111}. Included is the first detection of a midinfrared photon echo from a metallic surface, some 15 years after the analogous measurement on a semiconductor surface, which sets a precedent for the ability to manipulate and rephase polarization on a subpicosecond time scale on surfaces. For the C-O stretch in a strongly dipole-coupled CO layer we obtain a total linewidth of 5.6 cm-1, composed of a homogeneous width of 2.7 cm-1 and an inhomogeneous contribution of 3.0 cm-1. Pure dephasing is negligible at liquid nitrogen temperatures, making CO/Ir{111} an attractive model system for quantum computing.
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: Ian M
authors.initials: IM
authors.lastname: Lane
authors.forename: David A
authors.initials: DA
authors.lastname: King
authors.forename: Heike
authors.initials: H
authors.lastname: Arnolds