Christopher Wilson

Breakdown of the cross-Kerr scheme for Photon Counting

  1. Bixuan Fan,
  2. Anton F. Kockum,
  3. Joshua Combes,
  4. Göran Johansson,
  5. Io-chun Hoi,
  6. Christopher Wilson,
  7. Per Delsing,
  8. G. J. Milburn,
  9. and Thomas M. Stace
We show, in the context of single photon detection, that an atomic three-level model for a transmon in a transmission line does not support the predictions of the nonlinear polarisability
model known as the cross-Kerr effect. We show that the induced displacement of a probe in the presence or absence of a single photon in the signal field, cannot be resolved above the quantum noise in the probe. This strongly suggests that cross-Kerr media are not suitable for photon counting or related single photon applications. Our results are presented in the context of a transmon in a one dimensional microwave waveguide, but the conclusions also apply to optical systems.
arxiv pdf