Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Controlling the polarisation correlation of photon pairs from a
  charge-tuneable quantum dot   Correlation between the rectilinear polarisations of the photons emitted from
the biexciton decay in a single quantum dot is investigated in a device which
allows the charge-state of the dot to be controlled. Optimising emission from
the neutral exciton states maximises the operating efficiency of the biexciton
decay. This is important for single dot applications such as a triggered source
of entangled photons. As the bias on the device is reduced correlation between
the two photons is found to fall dramatically as emission from the negatively
charged exciton becomes significant. Lifetime measurements demonstrate that
electronic spin-scattering is the likely cause.

37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th