Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum Imaging with Undetected Photons   Indistinguishable quantum states interfere, but the mere possibility of
obtaining information that could distinguish between overlapping states
inhibits quantum interference. Quantum interference imaging can outperform
classical imaging or even have entirely new features. Here, we introduce and
experimentally demonstrate a quantum imaging concept that relies on the
indistinguishability of the possible sources of a photon that remains
undetected. Our experiment uses pair creation in two separate down-conversion
crystals. While the photons passing through the object are never detected, we
obtain images exclusively with the sister photons that do not interact with the
object. Therefore the object to be imaged can be either opaque or invisible to
the detected photons. Moreover, our technique allows the probe wavelength to be
chosen in a range for which suitable sources and/or detectors are unavailable.
Our experiment is a prototype in quantum information where knowledge can be
extracted by and about a photon that is never detected.

18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex