Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Photon phase shift at the few-photon level and optical switching by a
  quantum dot in a microcavity   We exploit the nonlinearity arising from the spin-photon interaction in an
InAs quantum dot to demonstrate phase shifts of scattered light pulses at the
single-photon level. Photon phase shifts of close to 90 degrees are achieved
using a charged quantum dot in a micropillar cavity. We also demonstrate a
photon phase switch by using a spin-pumping mechanism through Raman transitions
in an in-plane magnetic field. The experimental findings are supported by a
theoretical model which explores the dynamics of the system. Our results
demonstrate the potential of quantum dot-induced nonlinearities for quantum
information processing.

6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th