Fig. 3: Experimental demonstration of fermion parity measurements.
From: Interferometric single-shot parity measurement in InAs–Al hybrid devices
Measurements in device A (measurement A1) in the (B∥, VWP1) parameter regime identified through the tune-up procedure discussed in the main text and Section 4 of the Supplementary Information; specifically, VWP1 = −1.8314 V and B∥ = 1.8 T. The raw rf signal has been converted to complex \({\widetilde{C}}_{{\rm{Q}}}\) by the method described in Section 3.1 of the Supplementary Information. a,d, Time traces at Bx values corresponding to minimal (panel a) and maximal (panel d) values of ΔCQ for a fixed choice of VQD2 close to charge degeneracy. b,e, Histograms of complex \({\widetilde{C}}_{{\rm{Q}}}\) for the time trace shown in panels a and d. c,f, Histograms of the real part \({\rm{Re}}{\widetilde{C}}_{{\rm{Q}}}\) with Gaussian fits for an extraction of the SNR = δ/(σ1 + σ2) = 5.01, the details of which are given in Section 3.3 of the Supplementary Information. g, Histogram of dwell times aggregated over all values of Bx, in which the signal shows bimodality. Fitting to an exponential shows that the up and down dwell times agree to within the standard error on the fits: 2.05 ± 0.07 ms and 2.02 ± 0.07 ms, respectively. h, Histogram of \({\widetilde{C}}_{{\rm{Q}}}\) values as a function of Bx, showing clear bimodality that is flux-dependent with period h/2e. The vertical arrows indicate the Bx values at which the time traces in panels a and d were taken. i, Kurtosis in the measured quantum capacitance, \(K(\text{Re}{\widetilde{C}}_{{\rm{Q}}})\), of dot 2 as a function of Bx (which controls Φ) and ΔVQD2, the change in dot plunger gate voltage from the starting point of the scan (which controls the dot 2 detuning). The dashed red rectangle indicates the ΔVQD2 value at which the data in the other panels were taken.
