General method for extracting the quantum efficiency of dispersive qubit readout in circuit QED

General method for extracting the quantum efficiency of dispersive qubit readout in circuit QED

Bultink, C.C. (TU Delft QCD/DiCarlo Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)
Tarasinski, B.M. (TU Delft QCD/DiCarlo Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)
Haandbæk, N. (Zurich Instruments AG)
Poletto, S. (TU Delft QCD/DiCarlo Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)
Haider, S.N. (TU Delft BUS/General; TU Delft QuTech Advanced Research Centre; TNO)
Michalak, D.J. (Intel Labs)
Bruno, A. (TU Delft QCD/DiCarlo Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)
DiCarlo, L. (TU Delft QCD/DiCarlo Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)

2018

We present and demonstrate a general three-step method for extracting the quantum efficiency of dispersive qubit readout in circuit QED. We use active depletion of post-measurement photons and optimal integration weight functions on two quadratures to maximize the signal-to-noise ratio of the non-steady-state homodyne measurement. We derive analytically and demonstrate experimentally that the method robustly extracts the quantum efficiency for arbitrary readout conditions in the linear regime. We use the proven method to optimally bias a Josephson traveling-wave parametric amplifier and to quantify different noise contributions in the readout amplification chain.

http://resolver.tudelft.nl/uuid:40d9eee9-d6b4-4722-b3eb-3b0637904b2f

https://doi.org/10.1063/1.5015954

0003-6951

Applied Physics Letters, 112 (9)

Accepted Author Manuscript

Institutional Repository

journal article

© 2018 C.C. Bultink, B.M. Tarasinski, N. Haandbæk, S. Poletto, S.N. Haider, D.J. Michalak, A. Bruno, L. DiCarlo