Markov chain Monte Carlo detector tomography applied to a NbTiN nanobridge

F F. B. Baalbergen (Huygens-Kamerlingh Onnes Laboratory, Leiden University 1 , P.O. Box 9504, 2300RA Leiden,) I I. E. Zadeh (Department of Imaging Physics (ImPhys), Faculty of Applied Sciences, Delft University of Technology 2 , 2628CJ Delft,) M M. P. van Exter (Huygens-Kamerlingh Onnes Laboratory, Leiden University 1 , P.O. Box 9504, 2300RA Leiden,) M M. J. A. de Dood (Huygens-Kamerlingh Onnes Laboratory, Leiden University 1 , P.O. Box 9504, 2300RA Leiden,)

Abstract

We demonstrate the use of a flexible and highly accurate Markov chain Monte Carlo quantum detector tomography method as a minimization algorithm to best describe the response of an efficient 120 nm wide NbTiN superconducting nanobridge single photon detector. Separation of the internal quantum efficiency and external quantum efficiency is possible due to the difference in saturation behavior of an ideal one-photon threshold detector as compared to a detector with non-unity one-photon internal quantum efficiency. From a statistical analysis of our measurements (at T=(4.23 ± 0.01) K, I=(29.4 ± 0.1) μA, I/Iswitch=(0.90 ± 0.01)), we find an external quantum efficiency of η=(1.60 ± 0.05)×10−6, a one-photon internal quantum efficiency of p1=0.568 ± 0.008, and a unity multi-photon (two or more) internal quantum efficiency.

Article Details

Volume / Issue Vol. 126, Issue 24
Published June 16, 2025
ISSN 0003-6951
Publisher American Institute of Physics

Journal Info

Applied Physics Letters

American Institute of Physics

ISSN: 0003-6951 Physical Sciences

Authors (4)

F

F. B. Baalbergen

Huygens-Kamerlingh Onnes Laboratory, Leiden University 1 , P.O. Box 9504, 2300RA Leiden,

I

I. E. Zadeh

Department of Imaging Physics (ImPhys), Faculty of Applied Sciences, Delft University of Technology 2 , 2628CJ Delft,

M

M. P. van Exter

Huygens-Kamerlingh Onnes Laboratory, Leiden University 1 , P.O. Box 9504, 2300RA Leiden,

M

M. J. A. de Dood

Huygens-Kamerlingh Onnes Laboratory, Leiden University 1 , P.O. Box 9504, 2300RA Leiden,