Fig. 2: Measurement sequence for probing resonator-qubit coupling.
a Echo pulse sequence used to measure the exchange splitting of right qubit (QR) while driving the resonator using the RF gate of left qubit (QL). Gate is marked dark green in cartoon inset. Purple/orange shading is to indicate DQD occupation (0,2)/(1,1). b Exchange oscillations, shown by plotting the triplet probability P(T0) as a function of δt, is measured at several drive frequencies and indicate the qubit-resonator interaction near the resonator frequency ωr. c Two line cuts at different values of drive frequency (ωd) reveal a phase shift and rapid qubit dephasing when the drive frequency is close to the resonator frequency ωr/2π = 0.88 GHz. The decay envelopes fit to a Gaussian decay function given by \({T}_{2}^{*}\). d Extracted values of the change in energy splitting, δJ, as a function of ωd fit to a Lorentzian function to extract resonator decay rate κ, resonance frequency ωr and coupling strength χ.
