Resistance fluctuation spectroscopy of the superconducting transition in epitaxial TiN films
- Resource Type
- Authors
- Baeva, E. M.; Kolbatova, A. I.; Titova, N. A.; Saha, S.; Boltasseva, A.; Bogdanov, S.; Shalaev, V.; Semenov, A. V.; Goltsman, G. N.; Khrapai, V. S.
- Source
- Subject
- Superconductivity (cond-mat.supr-con)
Condensed Matter::Materials Science
Condensed Matter - Mesoscale and Nanoscale Physics
Condensed Matter - Superconductivity
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
FOS: Physical sciences
- Language
We investigate the impact of various fluctuation mechanisms on the time-averaged resistance and noise performance in superconducting devices based on epitaxial titanium nitride (TiN) films. We show that a very large noise at the resistive transition originates from spontaneous resistance (R) fluctuations. These fluctuations are characterized by a Lorentzian spectrum and a correlation time equal to that of electron energy relaxation time. The observed R-fluctuations in turn originate from temperature (T) fluctuations due to spontaneous energy exchange between the electron system and the thermal bath. We present a model that describes the broadening of the resistive transition by T-fluctuations, and agrees well with data for thicker TiN samples. In thinner films, we propose an additional effect of surface magnetic disorder that can explain the deviations from the model. Our results point to new mechanisms that can significantly affect resistive properties of superconductors.
Comment: accompanies "T-fluctuations and dynamics of the resistive transition in thin superconducting films" by Baeva et al