Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nanocrystalline superconducting $\gamma$-Mo$_2$N ultra-thin films for
  single-photon detectors   We analyze the influence of the surface passivation produced by oxides on the
superconducting properties of $\gamma$-Mo$_2$N ultra-thin films. The
superconducting critical temperature of thin films grown directly on Si (100)
with those using a buffer and a capping layer of AlN are compared. The results
show that the cover layer avoids the presence of surface oxides, maximizing the
superconducting critical temperature for films with thicknesses of a few
nanometers. We characterize the flux-flow instability measuring current-voltage
curves in a 6.4 nm thick Mo$_2$N film with a superconducting critical
temperature of 6.4 K. The data is analyzed using the Larkin and Ovchinnikov
model. Considering self-heating effects due to finite heat removal from the
substrate, we determine a fast quasiparticle relaxation time $\approx$ 45 ps.
This value is promising for its applications in single-photon detectors.

37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th