Figure 3
From: Noise of a superconducting magnetic flux sensor based on a proximity Josephson junction
Noise measurements. (a) Power spectral density of the measured voltage noise at Φ = 0 for the indicated values of the bias voltage V (blue dots), plotted on a semilogarithmic scale. The solid lines are fits to Eq. 1. (b) Bias dependence of the peak height \({R}_{{\rm{eff}}}^{2}{S}_{{\rm{I}}}\), extracted from fits to Eq. 1, for a few equally spaced values of magnetic flux between Φ = 0 (red solid line) and Φ = 0.5 Φ0 (blue solid line). (c) Total current noise S I vs. the DC bias, measured at T = 4.2 K with the junction in the normal state, and at T = 60 mK in the superconducting state, together with the theoretical predictions (see text for details). The dashed horizontal line indicates the background noise level, independent of V and Φ.
