Differential-phase-shift quantum key distribution using heralded narrow-band single photons

published_or_final_versio

TRANSIENT STUDY OF NON-EQUILIBRIUM SUPERCONDUCTOR USING PICOSECOND LIGHT-PULSES

[[fileno]]2010127010041[[department]]物理

Observation of two diffusion channels in a single diffusion measurement: CO on P-contaminated Pt(111)surface

We report that, for the first time, two diffusion channels are simultaneously observed on a P-contaminated Pt(111) surface in a single grating smearing measurement via diffusion by a linear optical diffraction method. While the slow channel is accordingly identified as the terrace diffusion, the fast one is identified as diffusion over the phosphorus-contaminated surface regions. (C) 1999 Elsevier Science B.V. All rights reserved

Desorption of polyatomic molecules from the Pt(111) surface by femtosecond laser radiation

We have experimentally studied femtosecond laser induced desorption of polyatomic molecules (NH3, ND3) from Pt (111), as a function of laser fluence and laser pulse duration (FWHM) from 120 fs to 1.0 ps. We found that the desorption yield does not depend on pulse width, in contrast to the results of a previously studied system, CO on the same metal surface. In addition, no isotope effect between NH3 and ND3 was observed. All these data are consistent with a thermal desorption mechanism instead of a hot-electron mediated process. (C) 2001 American Institute of Physics

Experimental study of surface diffusion rate enhancement along steps: CO on Pt(111)

Surface diffusion of CO parallel to steps on vicinal Pt(lll) surfaces has been studied by a linear optical diffraction method. Other than the two normal diffusion channels, namely diffusion over terraces and along step edges, a third channel, which enhances diffusion significantly even at low temperatures, is observed for the first time. The new channel exists only on A- and AB-type stepped surfaces but not on B-type stepped surfaces. (c) 1999 Elsevier Science B.V. All rights reserved

Femtosecond desorption of CO from metal surfaces: the role of the 2 pi{*}-derived states

We critically examined femtosecond desorption of CO from various metal surfaces. We found that the energy locations of the observe 2 pi{*}-derived states commonly featured in all theoretical models, are too high to be effectively excited by the laser generated photoelectrons. This difficulty can be resolved if we adopt the `Adiabatic Model' of Jennison et al. predicting the existence of short-lived antibonding states, at lower energy and can be excited by the photoelectrons, allowing desorption to occur. (C) 2001 Elsevier Science B.V. All rights reserved

On the mechanism limiting CO diffusion perpendicular to steps on Pt(111)

From the surface diffusion data perpendicular to steps, we deduced that the Schwoebel barrier for CO molecules on Pt(lll) is very small and could even be negative with the help of the known additional trapping energy at the step edges from independent measurements. This result indicates that the slow down of diffusion perpendicular to steps is likely due to the trapping well at the step edges. (C) 1999 Elsevier Science B.V. All rights reserved