Eur. Phys. J. B 47, 495-501 (2005)
https://doi.org/10.1140/epjb/e2005-00351-8

Spectral cut-off in the efficiency of the resistive state formation caused by absorption of a single-photon in current-carrying superconducting nano-strips

¹ DLR Institute of Planetary Research, Rutherfordstr. 2, 12489 Berlin, Germany
² Physics Institute, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
³ Institute of Micro- and Nano-Electronic Systems, University of Karlsruhe, Hertzstr. 16, 76187 Karlsruhe, Germany

Corresponding author: ^a alexei.semenov@dlr.de

Received: 25 September 2004
Revised: 18 August 2005
Published online: 17 November 2005

Abstract

We have studied supercurrent-assisted formation of the resistive state in nano-structured disordered superconducting Nb(N) films after absorption of a single optical to near-infrared photon. The efficiency of the resistive state formation has a pronounced spectral cut-off; corresponding threshold photon energy decreases with the bias current. Analysis of the experimental data in the framework of the refined hot-spot model suggests that the quantum yield for near-infrared photons increases with the photon energy. Relaxation of the resistive state depends on the photon energy making the phenomena feasible for the development of energy resolving single-photon detectors.