Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermal properties of NbN single-photon detectors   We investigate thermal properties of a NbN single-photon detector capable of
unit internal detection efficiency. Using an independent calibration of the
coupling losses we determine the absolute optical power absorbed by the NbN
film and, via a resistive superconductor thermometry, the thermal resistance
Z(T) of the NbN film in dependence of temperature. In principle, this approach
permits a simultaneous measurement of the electron-phonon and phonon-escape
contributions to the energy relaxation, which in our case is ambiguous for
their similar temperature dependencies. We analyze the Z(T) within the
two-temperature model and impose an upper bound on the ratio of electron and
phonon heat capacities in NbN, which is surprisingly close to a recent
theoretical lower bound for the same quantity in similar devices.

28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con