Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Few-photon all-optical phase rotation in a quantum-well micropillar
  cavity   Photonic platforms are an excellent setting for quantum technologies because
weak photon-environment coupling ensures long coherence times. The second key
ingredient for quantum photonics is interactions between photons, which can be
provided by optical nonlinearities in the form of cross-phase-modulation (XPM).
This approach underpins many proposed applications in quantum optics and
information processing, but achieving its potential requires strong
single-photon-level nonlinear phase shifts and also scalable nonlinear
elements. In this work we show that the required nonlinearity can be provided
by exciton-polaritons in micropillars with embedded quantum wells. These
combine the strong interactions of excitons with the scalability of
micrometer-sized emitters. We observe XPM up to $3 \pm 1$ mrad per particle
using laser beams attenuated to below single photon average intensity. With our
work serving as a first stepping stone, we lay down a route for quantum
information processing in polaritonic lattices.

27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin