Readout uses a resonator coupled to the qubit. The qubit state shifts the resonator frequency by +/- chi, and a probe tone converts that shift into a voltage we can classify. This page shows how probe frequency and noise determine fidelity.
Dispersive Readout
Lorentzian responseSingle resonator
chi6.0 MHz
kappa8 MHz
Probe delta0.0 MHz
Contrast: 0.00
|0> response: 0.31|1> response: 0.31Probe where the two curves are most separated.