Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Photon thermalization and a condensation phase transition in an
  electrically pumped semiconductor microresonat   We report on an experimental study of photon thermalization and condensation
in a semiconductor microresonator in the weak-coupling regime. We measure the
dispersion relation of light and the photon mass in a single-wavelength,
broad-area resonator. The observed luminescence spectrum is compatible with a
room-temperature, thermal-equilibrium distribution. A phase transition,
identified by a saturation of the population at high energies and a superlinear
increase of the occupation at low energy, takes place when the phase-space
density is of order unity. We explain our observations by Bose-Einstein
condensation of photons in equilibrium with a particle reservoir and discuss
the relation with laser emission.

27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
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The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
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The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org