Fig. 2
From: Joule overheating poisons the fractional ac Josephson effect in topological Josephson junctions
Partial fractional AC Josephson effect. a, b Shapiro maps displaying the differential resistance dV/dI versus rf power Prf applied to the antenna and dc current I measured at frf = 3.5 GHz in (a) and 1 GHz in (b). White numbers indicate the Shapiro steps index. c, d Voltage V in units of frfh/2e versus I extracted from the Shapiro map in (a, b) respectively at two different Prf values. The corresponding Prf values are indicated by the black arrows in (a, b). e Shapiro map displaying dV/dI versus Prf and I, measured at a different frequency frf = 0.953 GHz during a second cooling of the sample, and zoomed on the first resistive node. The white arrow indicates twice the residual supercurrent \(\left( {2 \times I_0^{k = 1}} \right)\) at the first resistive node
