Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tensor polarizability and dispersive quantum measurement of multilevel
  atoms   Optimally extracting information from measurements performed on a physical
system requires an accurate model of the measurement interaction. Continuously
probing the collective spin of an Alkali atom cloud via its interaction with an
off-resonant optical probe is an important example of such a measurement where
realistic modeling at the quantum level is possible using standard techniques
from atomic physics. Typically, however, tutorial descriptions of this
technique have neglected the multilevel structure of realistic atoms for the
sake of simplification. In this paper we account for the full multilevel
structure of Alkali atoms and derive the irreducible form of the polarizability
Hamiltonian describing a typical dispersive quantum measurement. For a specific
set of parameters, we then show that semiclassical predictions of the theory
are consistent with our experimental observations of polarization scattering by
a polarized cloud of laser-cooled Cesium atoms. We also derive the
signal-to-noise ratio under a single measurement trial and use this to predict
the rate of spin-squeezing with multilevel Alkali atoms for arbitrary detuning
of the probe beam.

2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph