Fig. 5
From: Gate-controlled quantum dots and superconductivity in planar germanium
Tunable induced superconductivity in the Ge quantum well. a SEM image of the JoFET device with a gap of 100 nm. Scale bar is 200 nm. b Device schematic using the colour scheme of Fig. 2b. Superconducting transport through the quantum well is illustrated. c Source-drain voltage as a function of the applied current at a top gate voltage of VTG = −1.46 V. A flat plateau with zero resistance is observed up to a critical current of Ic ≈ 12 nA as a clear signature of a supercurrent through the device. d The critical current can be modulated by tuning the top gate voltage, as shown in the colour plot of the current dependence of the device resistance as a function of VTG, where ISD was swept from negative to positive values
