Phase preserving amplification near the quantum limit with a Josephson Ring Modulator

References

Supplementary figure 1. Phase of the “cis-gain” $r_{1}$ of the JPC as a function of the drive frequency for different values of the pump power measured at port 1. Solid lines correspond to the theoretical expressions of the phase extracted from expression (3) and obtained for different values of the fit parameter $|\rho|$.

Supplementary figure 2. Dynamic range of the amplifier. The figure shows the reflected power at port 1 of a continuous microwave of frequency $f_{1}$=1.631 GHz as a function of its input power for different value of the gain $G$. The gain $G$=0 (pump off) is given as reference. The solid lines of slope one show the regime where the gain is independent of the input power. The curves start to saturate when the output power reach approximatively -105 dB, corresponding to an estimate of the microwave current in the junction taken of order of their critical current bergeal .

Supplementary figure 3. Noise measurement set-up and SEM picture of the nanowire embedded in the thick CPW transmission line. The device can be heated by a dc current applied through a current divider at base temperature (resistors $R_{1}$ and $R_{2}$) and a bias tee. The high-frequency port of the bias tee is connected to the JPC through a circulator.