Extended Data Fig. 2: Calibration of the field polarization.
a, The Rabi frequencies of rotational σ+ (green), π (blue), and σ− (orange) transitions at low microwave power as a function of the phase shift ϕ between the antenna feeds. The error bars show the fitting error of the Rabi oscillations. The solid lines are fits to equation (4). b, Ellipticity of the microwave field in the frame of the microwave. The data points show the ellipticity angle ξ calulated from the data in a. The error bars denote the uncertainty of ξ that originates from the projection from the frame of the magnetic offset field to the frame of the microwave field due to the unknown phase relation between the three field components. The gray band is calculated from the fit functions shown in a and its width considers the uncertainty of the microwave orientation and the uncertainty of the offset phases ϕ0.
