Cryogenic amplifier with low input-referred voltage noise calibrated by shot noise measurement Project supported by the National Natural Science Foundation of China (Grant No. 11474008), the National Key Research and Development Program of China (Grant No. 2016YFA0300904), and the National Basic Research Program of China (Grant No. 2011CBA00106). |
(color online) Differential resistance as a function of temperature. Inset: Upper right shows the SEM image of the Al/AlOx/Al tunneling junction (red circle). Lower left shows the differential resistance as a function of the current bias at 4.6 K. |