Fig. 5. Amplitude dependence of rectification.

a Top: the I–V of JJ1 on D1 (dark blue) with nearly maximum nonreciprocity, I_c+/∣I_c−∣. It is measured using right-corner bias, $I=I_{ac}\sin \left(2\pi ft\right)$. Green line represents the ideal case with infinite nonreciprocity, I_c− = 0. Bottom: Time dependencies of voltages during one ac-period at f = 23 Hz for different bias amplitudes. b Top: time-averaged dc-voltage as a function of ac-bias amplitude for JJ1 on D1 at T ≃ 6.9 K. Green line represents the ideal case, 〈V〉_max = I_acR_n/π. Bottom: rectification efficiency, 〈V〉/〈V〉_max, versus ac-bias amplitude. c, d These show similar data for JJ1 on D2 at T = 6.3 K. Top panel in c shows I-Vs with maximum nonreciprocities obtained at H = 0.7 Oe (red) and -0.7 Oe (blue) without AV. d and bottom panel in c represent analysis of rectification for the red I-V with I_c+ < ∣I_c−∣, leading to a positive rectified voltage.