Thermal Properties of NbN Single-Photon Detectors
E. M. Baeva (Chemistry Faculty of M. V. Lomonosov Moscow State University, National Research University Higher School of Economics (HSE University))
M. V. Sidorova (Chemistry Faculty of M. V. Lomonosov Moscow State University, Deutsches Zentrum für Luft- und Raumfahrt (DLR))
A. A. Korneev (Chemistry Faculty of M. V. Lomonosov Moscow State University, National Research University Higher School of Economics (HSE University))
K. V. Smirnov (LLC Superconducting Nanotechnology (Scontel), National Research University Higher School of Economics (HSE University), Moscow State University of Education)
A. V. Divochy (Chemistry Faculty of M. V. Lomonosov Moscow State University, LLC Superconducting Nanotechnology (Scontel))
P. V. Morozov (LLC Superconducting Nanotechnology (Scontel))
P. I. Zolotov (LLC Superconducting Nanotechnology (Scontel), Chemistry Faculty of M. V. Lomonosov Moscow State University, National Research University Higher School of Economics (HSE University))
Yu B. Vakhtomin (Chemistry Faculty of M. V. Lomonosov Moscow State University)
T. M. Klapwijk (TU Delft - Applied Sciences, Kavli institute of nanoscience Delft, TU Delft - QN/Klapwijk Lab, Chemistry Faculty of M. V. Lomonosov Moscow State University)
undefined More Authors (External organisation)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
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 resistive superconductor thermometry, the temperature dependence of the thermal resistance Z(T) of the NbN film. In principle, this approach permits simultaneous measurement of the electron-phonon and phonon-escape contributions to the energy relaxation, which in our case is ambiguous because of the similar temperature dependencies. We analyze Z(T) with a twoerature 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.