• A
  • A
  • A
  • ABC
  • ABC
  • ABC
  • А
  • А
  • А
  • А
  • А
Regular version of the site

Article

Superconductivity in highly disordered NbN nanowires

Nanotechnology. 2016. Vol. 27. No. 47. P. 1-8.
Arutyunov K., Ramos-Alvares A., Semenov A., Korneeva Y. P., An P. P., Korneev A., Murphy A., Bezryadin A., Gol'tsman G. N.

The topic of superconductivity in strongly disordered materials has attractedsignificant attention.
These materials appear to be rather promising for fabrication of various nanoscale devices such as
bolometers and transition edge sensors of electromagnetic radiation. The vividly debated subject of
intrinsic spatial inhomogeneity responsible for thenon-Bardeen–Cooper–Schrieffer relation
between the superconducting gap and the pairing potential is crucial both for understanding the
fundamental issues of superconductivity in highly disordered superconductors, and for theoperation
of corresponding nanoelectronic devices. Here we report an experimental study of theelectron
transport properties of narrow NbN nanowires with effective cross sections of the order of the
debated inhomogeneity scales. The temperature dependence of the critical current follows the
textbook Ginzburg–Landau prediction for thequasi-one-dimensional superconducting channel
Ic∼(1-T/Tc)3/2. We find that conventional models based on the thephase slip mechanism provide
reasonable fits for the shape of R(T) transitions. Better agreement with R(T) data can be achieved
assuming theexistence of short ‘weak links’ with slightly reduced local critical temperature Tc.
Hence, one may conclude that an ‘exotic’ intrinsic electronic inhomogeneity either does not exist in
our structures, or, if it doesexist, itdoes not affect their resistive state properties, or does not
provide any specific impact distinguishablefrom conventional weak links.