Surface Observation of a Potassium-Doped C₆₀ Thin Film by Scanning Tunneling Microscopy

Abstract

Two standard criteria of the photon antibunching for non-stationary fields are compared. A new criterion, obtained by direct application of the Cauchy-Schwarz inequality, is proposed. All three definitions, based on the two-time correlation functions, are equivalent for stationary fields. However, the photon antibunching in the non-stationary regime is demonstrated to be not uniquely defined, since different criteria can lead to self-contradictory predictions. As an example, photon correlations of the signal mode in the parametric frequency converter are analysed analytically.

Calculation of images of orientedC60molecules using molecular orbital theory

“…Naturally, this interest has extended to STM, yielding many fascinating studies and images involving surface-adsorbed C 60 molecules exposed to electronrich doping agents. 9,[29][30][31]34,35 Unfortunately, the doping agents ͑usually alkali metals because of their high electropositivity and volatility͒ do not show up in the resulting STM images and so their effect on the local site symmetry is uncertain. However, their presence on the surface could well be expected to perturb the MOs to an even greater extent than that caused by the surface alone, perhaps leading to complete loss of degeneracy.…”