Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonclassical Light from Exciton Interactions in a Two-Dimensional
  Quantum Mirror   Excitons in a semiconductor monolayer form a collective resonance that can
reflect resonant light with extraordinarily high efficiency. Here, we
investigate the nonlinear optical properties of such atomistically thin mirrors
and show that finite-range interactions between excitons can lead to the
generation of highly non-classical light. We describe two scenarios, in which
optical nonlinearities arise either from direct photon coupling to excitons in
excited Rydberg states or from resonant two-photon excitation of Rydberg
excitons with finite-range interactions. The latter case yields conditions of
electromagnetically induced transparency and thereby provides an efficient
mechanism for single-photon switching between high transmission and reflectance
of the monolayer, with a tunable dynamical timescale of the emerging
photon-photon interactions. Remarkably, it turns out that the resulting high
degree of photon correlations remains virtually unaffected by Rydberg-state
decoherence, in excess of non-radiative decoherence observed for ground-state
excitons in two-dimensional semiconductors. This robustness to imperfections
suggests a promising new approach to quantum photonics at the level of
individual photons.

1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org