Controlling supercurrents using single-walled carbon nanotube weak links

We have investigated proximity-induced supercurrents in single-walled carbon nanotubes. Phase diffusion is found to be present in the maximum measured supercurrent of 4.8 nA, which results in a minimum of 100Ω zero bias resistance in superconducting state. We also observe that the supercurrent is very sensitive to the measurement bandwidth and large phase fluctuations can even destroy the supercurrents. Our results shed light on the methods of how to improve the performance of high frequency superconducting single-walled nanotube devices.Peer reviewe