Mapping of the Quantum Efficiency of a Superconducting Single Electron Detector

Adrian Lupascu (1, 2) , Andreas Emmert (1) , Michel Brune (1) , Gilles Nogues (3) , Michael Rosticher (4) , F.-R. Ladan (4) , J.-P. Maneval (4) , J.-C. Villegier (5)

1 LKB (Lhomond) - Laboratoire Kastler Brossel
2 Institute for Quantum Computing
3 NEEL - NPSC - Nanophysique et Semiconducteurs
4 LPA - Laboratoire Pierre Aigrain
5 SPSMS - UMR 9001 - Service de Physique Statistique, Magnétisme et Supraconductivité

Superconducting NbN wires have recently received attention as detectors for visible and infrared photons [1]. We present experiments in which we use a NbN wire for high-efficiency (similar or equal to 40%) detection of single electrons with keV energy. We use the beam of a scanning electron microscope as a focussed, stable, and calibrated electron source. Scanning the beam over the surface of the wire provides a map of the detection efficiency. This map shows features as small as 150 nm, revealing wire inhomogeneities. The intrinsic resolution of this mapping method, superior to optical methods, provides the basis of a characterization tool relevant for photon detectors.

Domaines: Supraconductivité [cond-mat.supr-con]

Adrian Lupascu, Andreas Emmert, Michel Brune, Gilles Nogues, Michael Rosticher, et al.. Mapping of the Quantum Efficiency of a Superconducting Single Electron Detector. IEEE Toronto International Conference on Science and Technology for Humanity, Sep 2009, TORONTO, Canada. pp.1011. ⟨hal-00534044⟩