Fig. 3
Back-gate modulation of the interface ground state. a Sheet resistivity versus temperature (R–T) curves as a function of VBG from −46 to 90 V with fixed VTG = 1.8 V. b The second-order derivative calculated using a spline fit of the R–T curves shown in a. Red circles and blue squares indicate the local maxima of the peaks, defining TP and TF. Curve colours are matched between a and b. c Phase diagram for back-gating with fixed VTG = 1.8 V. Red circles, blue squares, and blue triangles represent TP, TF, and TC, respectively. Normal state here indicates a non-superconducting state. Error bars are defined by the full width of the second derivative peaks for TP and TF. TC is defined as the temperature at which the sheet resistivity drops to 1% of the normal state RN (400 mK). The lowest temperature measured for our R–T curves is 40 mK, so data points estimated to be <40 mK are plotted with arrows. Background colours are guides to the eye indicating the different regimes
