Fig. 4: Evidence for flux-flow instability.

a A schematic depicting ‘S’ shaped I–V characteristics. which has two unstable points, denoted by asterisk symbol. When the I–V measurement is performed in current bias mode, a voltage instability is observed when the value of current is close to unstable point leading to an abrupt increase/decrease in the voltage drop. Further, the voltage instability under backward current sweep happens at a lower current than in the forward sweep leading to a hysteresis. b Current dependent vortex velocity at 1.26 K for 7 nm AlO_x/KTaO₃ (111) (I along [\(11\bar{2}\)]). We emphasize that this whole analysis only holds only in between the region marked with the dashed lines²⁸. c Magnetic field dependent I–V curves measured in current bias mode for the Hall bar along [\(11\bar{2}\)] on 7 nm AlO_x/KTaO₃ (111) sample at 1.31 K. Curves have been shifted upward for visual clarity. d Magnetic field evolution of normalized critical voltage (\(\frac{{V}^{* }}{\sqrt{{n}_{{{{{{{{\rm{f}}}}}}}}}{\xi }^{2}}}\)) calculated for Hall bar along [\(11\bar{2}\)] on 7 nm AlO_x/KTaO₃ (111) sample. The dotted line denotes expected behavior for 1/√B dependence.