Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Broadband photon-photon interactions mediated by cold atoms in a
  photonic crystal fiber   We demonstrate theoretically that photon-photon attraction can be engineered
in the continuum of scattering states for pairs of photons propagating in a
hollow-core photonic crystal fiber filled with cold atoms. The atoms are
regularly spaced in an optical lattice configuration and the photons are
resonantly tuned to an internal atomic transition. We show that the hard-core
repulsion resulting from saturation of the atomic transitions induces bunching
in the photonic component of the collective atom-photon modes (polaritons).
Bunching is obtained in a frequency range as large as tens of GHz, and can be
controlled by the inter-atomic separation. We provide a fully analytical
explanation for this phenomenon by proving that correlations result from a
mismatch of the quantization volumes for atomic excitations and photons in the
continuum. Even stronger correlations can be observed for in-gap two-polariton
bound states. Our theoretical results use parameters relevant for current
experiments with Rb atoms excited on the D2-line.

24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an