Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation of superabsorption by correlated atoms   Emission and absorption of light lie at the heart of light-matter
interaction. Although the emission and absorption rates are regarded as
intrinsic properties of atoms and molecules, various ways to modify these rates
have been sought in critical applications such as quantum information
processing, metrology and light-energy harvesting. One of the promising
approaches is to utilize collective behavior of emitters as in superradiance.
Although superradiance has been observed in diverse systems, its conceptual
counterpart in absorption has never been realized. Here, we demonstrate
superabsorption, enhanced cooperative absorption, by correlated atoms of
phase-matched superposition state. By implementing an
opposite-phase-interference idea on a superradiant state or equivalently a
time-reversal process of superradiance, we realized the superabsorption with
its absorption rate much faster than that of the ordinary ground-state
absorption. The number of photons completely absorbed for a given time interval
was measured to be proportional to the square of the number of atoms. Our
approach, breaking the limitation of the conventional absorption, can help
weak-signal sensing and advance efficient light-energy harvesting as well as
light-matter quantum interfaces.

8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol