Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Coherent acoustic vibration of metal nanoshells   Using time-resolved pump-probe spectroscopy we have performed the first
investigation of the vibrational modes of gold nanoshells. The fundamental
isotropic mode launched by a femtosecond pump pulse manifests itself in a
pronounced time-domain modulation of the differential transmission probed at
the frequency of nanoshell surface plasmon resonance. The modulation amplitude
is significantly stronger and the period is longer than in a gold nanoparticle
of the same overall size, in agreement with theoretical calculations. This
distinct acoustical signature of nanoshells provides a new and efficient method
for identifying these versatile nanostructures and for studying their
mechanical and structural properties.

25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph