a, b, Two independent sample recordings. Top and bottom panels show electrical and thermal conductance, respectively. The green- and yellow-shaded regions mark portions of the recordings that capture the rupture of a single-molecule junction to which the time-averaging scheme is applied, while the blue-shaded regions during the earlier portions of the withdrawal cycle represent recordings that contain events involving multi-molecule junctions. A clear last step can be identified in the electrical conductance traces (green-yellow region), indicating the breakdown of a single-molecule junction. As can be seen, there are also additional steps before the last step in the blue-shaded region. The corresponding thermal conductance traces that are shown below each electrical conductance trace do not reveal any thermal conductance steps, owing to the low signal-to-noise ratio. Insets, schematics of single-molecule junctions before and after rupture.