Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optimal detection of losses by thermal probes   We consider the discrimination of lossy bosonic channels and focus to the
case when one of the values for the loss parameter is zero, i.e., we address
the detection of a possible loss against the alternative hypothesis of an ideal
lossless channel. This discrimination is performed by inputting one-mode or
two-mode squeezed thermal states with fixed total energy. By optimizing over
this class of states, we find that the optimal inputs are pure, thus
corresponding to single- and two-mode squeezed vacuum states. In particular, we
show that for any value of the damping rate smaller than a critical value there
is a threshold on the energy that makes the two-mode squeezed vacuum state more
convenient than the corresponding single-mode state, whereas for damping larger
than this critical value two-mode squeezed vacua are always better. We then
consider the discrimination in realistic conditions, where it is unlikely to
have pure squeezing. Thus by fixing both input energy and squeezing, we show
that two-mode squeezed thermal states are always better than their single- mode
counterpart when all the thermal photons are directed into the dissipative
channel. Besides, this result also holds approximately for unbalanced
distribution of the thermal photons. Finally, we also investigate the role of
correlations in the improvement of detection. For fixed input squeezing
(single-mode or two-mode), we find that the reduction of the quantum Chernoff
bound is a monotone function of the two-mode entanglement as well as the
quantum mutual information and the quantum discord. We thus verify that
employing squeezing in the form of correlations (quantum or classical) is
always a resource for loss detection whenever squeezed thermal states are taken
as input.

0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex