Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Rationale for $10^{14}$ enhancement factor in single molecule Raman
  spectroscopy   We extend the Purcell's original idea [Phys. Rev. \textbf{69}, 682 (1946)] on
modification of photon spontaneous \textit{emission} rate to modification of
photon spontaneous \textit{scattering} rate. We find the interplay of local
incident field enhancement and local density of photon states enhancement in
close proximity to a silver nanoparticle may result in up to $10^{14}$-fold
rise of Raman scattering cross-section. Thus single molecule Raman detection is
found to be explained by consistent quantum electrodynamic description without
any chemical mechanism involved. A model of the so-called "hot points" in
surface enhanced spectroscopy has been elaborated as local areas with high
Q-factor at incident and scattered (emitted) light frequencies. For
verification of the model we consider further experiments including transient
Raman experiments to clarify incident field enhancement and scanning near-field
optical mapping of local density of photon states.

34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg