Microwave photon detection by an Al Josephson junction
Journal article, 2020

An aluminium Josephson junction (JJ), with a critical current suppressed by a factor of three compared with the maximal value calculated from the gap, is experimentally investigated for application as a threshold detector for microwave photons. We present the preliminary results of measurements of the lifetime of the superconducting state and the probability of switching by a 9 GHz external signal. We found an anomalously large lifetime, not described by the Kramers' theory for the escape time over a barrier under the influence of fluctuations. We explain it by the phase diffusion regime, which is evident from the temperature dependence of the switching current histograms. Therefore, phase diffusion allows for a significant improvement of the noise immunity of a device, radically decreasing the dark count rate, but it will also decrease the single-photon sensitivity of the considered threshold detector. Quantization of the switching probability tilt as a function of the signal attenuation for various bias currents through the JJ is observed, which resembles the differentiation between N and N + 1 photon absorption.

Phase diffusion

Microwaves

Photon counter

Aluminium

Switching current distribution

Josephson junction

Author

L. S. Revin

Russian Academy of Sciences

Nizhny Novgorod State Technical University

A. L. Pankratov

Lobachevsky University

Russian Academy of Sciences

Nizhny Novgorod State Technical University

A. V. Gordeeva

Nizhny Novgorod State Technical University

Anton A. Yablokov

Russian Academy of Sciences

Nizhny Novgorod State Technical University

I. V. Rakut

Nizhny Novgorod State Technical University

Lobachevsky University

V. O. Zbrozhek

Nizhny Novgorod State Technical University

Leonid Kuzmin

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Nizhny Novgorod State Technical University

Beilstein Journal of Nanotechnology

21904286 (eISSN)

Vol. 11 960-965

Subject Categories

Atom and Molecular Physics and Optics

Other Physics Topics

Condensed Matter Physics

DOI

10.3762/bjnano.11.80

More information

Latest update

8/20/2020