a–d Switching- (orange) and retrapping-current (blue) distributions for a 55-nm-wide YBCO nanowire at different temperatures. Source data are provided as a Source Data file. e Energy levels in the local minimum of the tilted washboard potential at different bias currents for the nanowire illuminated using 77 K black body radiation. Transitions between energy levels are shown using orange, magenta, and blue arrows. Escape in the resistive state by tunneling is indicated by red arrows.