Superconductivity dependent friction of water, nitrogen, and superheated He films adsorbed on Pb(111).

We report a quartz crystal microbalance study of sliding friction levels in N2, H2O, and superheated He films adsorbed on Pb(111) substrates alternating in and out of the superconducting state. Reductions in friction upon entry into the superconducting state are greater for N2 than He, consistent with a recent theory that linked electronic friction to adsorbate polarizability. Our work also reveals that repetitive cycling of an externally applied magnetic field may impact friction.