This article is cited in 7 papers

CONDENSED MATTER

Universal bottleneck for thermal relaxation in disordered metallic films

E. M. Baeva^ab, N. A. Titova^b, A. I. Kardakova^bc, S. V. Piatrusha^a, V. S. Khrapai<sup>ba

a</sup> Institute of Solid State Physics, Russian Academy of Sciences, Chernogolovka, Moscow region, 142432 Russia
^b Moscow State University of Education, Moscow, 119435 Russia
^c National Research University Higher School of Economics, Moscow, 101000 Russia

Abstract: We study the heat relaxation in current biased metallic films in the regime of strong electron–phonon coupling. A thermal gradient in the direction normal to the film is predicted, with a spatial temperature profile determined by the temperature-dependent heat conduction. In the case of strong phonon scattering, the heat conduction occurs predominantly via the electronic system and the profile is parabolic. This regime leads to the linear dependence of the noise temperature as a function of bias voltage, in spite of the fact that all the dimensions of the film are large compared to the electron–phonon relaxation length. This is in stark contrast to the conventional scenario of relaxation limited by the electron–phonon scattering rate. A preliminary experimental study of a 200-nm-thick NbN film indicates the relevance of our model for materials used in superconducting nanowire single-photon detectors.

Received: 27.11.2019
Revised: 04.12.2019
Accepted: 04.12.2019

DOI: 10.31857/S0370274X20020071

 English version: Journal of Experimental and Theoretical Physics Letters, 2020, 111:2, 104–108

Bibliographic databases:

• 
• 
•