3,551 research outputs found
Attosecond nanoplasmonic streaking of localized fields near metal nanospheres
Collective electron dynamics in plasmonic nanosystems can unfold on
timescales in the attosec- ond regime and the direct measurements of plasmonic
near-field oscillations is highly desirable. We report on numerical studies on
the application of attosecond nanoplasmonic streaking spectroscopy to the
measurement of collective electron dynamics in isolated Au nanospheres. The
plasmonic field oscillations are induced by a few-cycle NIR driving field and
are mapped by the energy of photoemitted electrons using a synchronized,
time-delayed attosecond XUV pulse. By a detailed analysis of the amplitudes and
phase shifts, we identify the different regimes of nanoplasmonic streaking and
study the dependence on particle size, XUV photoelectron energy and emission
position. The simulations indicate that the near-fields around the
nanoparticles can be spatio-temporally reconstructed and may give detailed
insight into the build-up and decay of collective electron motion.Comment: Revised versio
On the Experimental Estimation of Surface Enhanced Raman Scattering (SERS) Cross Sections by Vibrational Pumping
We present an in-depth analysis of the experimental estimation of cross
sections in Surface Enhanced Raman Scattering (SERS) by vibrational pumping.
The paper highlights the advantages and disadvantages of the technique,
pinpoints the main aspects and limitations, and provides the underlying
physical concepts to interpret the experimental results. Examples for several
commonly used SERS probes are given, and a discussion on future possible
developments is also presented.Comment: To be submitted to J. Phys. Chem.
Enhancement factor distribution around a single SERS Hot-spot and its relation to Single Molecule detection
We provide the theoretical framework to understand the phenomenology and
statistics of single-molecule (SM) signals arising in Surface-Enhanced Raman
Scattering (SERS) under the presence of so-called electromagnetic hot-spots
(HS's). We show that most characteristics of the SM-SERS phenomenon can be
tracked down to the presence of tail-like (power law) distribution of
enhancements and we propose a specific model for it. We analyze, in the light
of this, the phenomenology of SM-SERS and show how the different experimental
manifestations of the effect reported in the literature can be analyzed and
understood under a unified ``universal'' framework with a minimum set of
parameters.Comment: 13 pages, 4 figures, submitted to J. Chem. Phy
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