Schemes for the observation of photon correlation functions in circuit QED with linear detectors
Marcus P. da Silva, Deniz Bozyigit, Andreas J. Wallraff, Alexandre Blais · Physical Review A · 2010
Correlations are important tools in the characterization of quantum fields, as they can be used to describe statistical properties of the fields, such as bunching and antibunching, as well as to perform field state tomography. Here we analyze experiments by Bozyigit et al. [Nat. Phys. (to appear), e-print arXiv:1002.3738] where correlation functions can be observed using the measurement records of linear detectors (i.e., quadrature measurements), instead of relying on intensity or number detectors. We also describe how large amplitude noise introduced by these detectors can be quantified and subtracted from the data. This enables, in particular, the observation of first- and second-order coherence functions of microwave photon fields generated using circuit quantum electrodynamics and propagating in superconducting transmission lines under the condition that noise is sufficiently low.