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Suppression of electronic friction on Nb films in the superconducting state


Investigations on the origins of friction are still scarce and controversial1,2,3,4. In particular, the contributions of electronic and phononic excitations are poorly known5,6,7,8,9,10,11. A direct way to distinguish between them is to work across the superconducting phase transition7,8,9,10,11,12. Here, non-contact friction13,14,15,16 on a Nb film is studied across the critical temperature TC using a highly sensitive cantilever oscillating in the pendulum geometry in ultrahigh vacuum. The friction coefficient Γ is reduced by a factor of three when the sample enters the superconducting state. The temperature decay of Γ is found to be in good agreement with the Bardeen–Cooper–Schrieffer theory12,17,18,19, meaning that friction has an electronic nature in the metallic state, whereas phononic friction dominates in the superconducting state. This is supported by the dependence of friction on the probe–sample distance d and on the bias voltage V. Γ is found to be proportional to d−1 and V2 in the metallic state, whereas Γd−4 and ΓV4 in the superconducting state. Therefore, phononic friction becomes the main dissipation channel below the critical temperature16.

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Figure 1: AFM topography image of the Nb film studied in the experiment.
Figure 2: Temperature variation of the friction coefficient Γ across the critical point Tc=9.2 K of Nb.
Figure 3: Distance dependence of the friction coefficient in the metallic and in the superconducting state of Nb.
Figure 4: Non-contact friction as a function of the bias voltage V in the metallic and superconducting state of Nb.


  1. Urbakh, M. & Meyer, E. Nanotribology: The renaissance of friction. Nature Mater. 9, 8–10 (2010).

    CAS  Article  Google Scholar 

  2. Dienwiebel, M. et al. Superlubricity of graphite. Phys. Rev. Lett. 92, 126101 (2004).

    Article  Google Scholar 

  3. Lantz, M. A., Wiesmann, D. & Gotsmann, B. Dynamic superlubricity and the elimination of wear on the nanoscale. Nature Nanotech. 4, 586–591 (2009).

    CAS  Article  Google Scholar 

  4. Socoliuc, A. et al. Atomic-scale control of friction by actuation of nanometer-sized contacts. Science 313, 207–210 (2006).

    CAS  Article  Google Scholar 

  5. Cannara, R. J. et al. Nanoscale friction varied by isotopic shifting of surface vibrational frequencies. Science 318, 780–783 (2007).

    CAS  Article  Google Scholar 

  6. Park, J. Y., Ogletree, D. F., Thiel, P. A. & Salmeron, M. Electronic control of friction in silicon pn junctions. Science 313, 186 (2006).

    CAS  Article  Google Scholar 

  7. Dayo, A., Alnasrallah, W. & Krim, J. Superconductivity-dependent sliding friction. Phys. Rev. Lett. 80, 1690–1693 (1998).

    CAS  Article  Google Scholar 

  8. Renner, R. L., Rutledge, J. E. & Taborek, P. Quartz microbalance studies of superconductivity-dependent sliding friction. Phys. Rev. Lett. 83, 1261 (1999).

    CAS  Article  Google Scholar 

  9. Bruschi, L. et al. Structural depinning of Ne monolayers on Pb at T<6.5 K. Phys. Rev. Lett. 96, 216101 (2006).

    CAS  Article  Google Scholar 

  10. Highland, M. & Krim, J. Superconductivity dependent friction of water, nitrogen, and superheated He films adsorbed on Pb(111). Phys. Rev. Lett. 96, 226107 (2006).

    CAS  Article  Google Scholar 

  11. Pierno, M. et al. Nanofriction of neon films on superconducting lead. Phys. Rev. Lett. 105, 016102 (2010).

    CAS  Article  Google Scholar 

  12. Persson, B. N. J. Electronic friction on a superconductor surface. Solid State Commun. 115, 145–148 (2000).

    CAS  Google Scholar 

  13. Stipe, B. C., Mamin, H. J., Stowe, T. D., Kenny, T. W. & Rugar, D. Noncontact friction and force fluctuations between closely spaced bodies. Phys. Rev. Lett. 87, 096801 (2001).

    CAS  Article  Google Scholar 

  14. Kuehn, S., Loring, R. F. & Marohn, J. A. Dielectric fluctuations and the origins of noncontact friction. Phys. Rev. Lett. 96, 156103 (2006).

    Article  Google Scholar 

  15. Kuehn, S., Marohn, J. A. & Loring, R. F. Noncontact dielectric friction. J. Phys. Chem. B 110, 14525–14528 (2006).

    CAS  Article  Google Scholar 

  16. Volokitin, A. I., Persson, B. N. J. & Ueba, H. Giant enhancement of noncontact friction between closely spaced bodies by dielectric films and two-dimensional systems. J. Exp. Theor. Phys. 104, 96–110 (2007).

    CAS  Article  Google Scholar 

  17. Persson, B. N. J. Sliding Friction (Springer, 2000).

    Book  Google Scholar 

  18. Bardeen, J., Cooper, L. N. & Schrieffer, J. R. Theory of superconductivity. Phys. Rev. 108, 1175–1204 (1957).

    CAS  Article  Google Scholar 

  19. Schrieffer, J. R. Theory of Superconductivity (Benjamin, 1966).

    Google Scholar 

  20. Rast, S., Gysin, U., Meyer, E. & Lee, D. W. in Fundamentals of Friction and Wear on the Nanoscale (eds Gnecco, E. & Meyer, E.) (Springer, 2007).

    Google Scholar 

  21. Gotsmann, B., Seidel, C., Anczykowski, B. & Fuchs, H. Conservative and dissipative tip–sample interaction forces probed with dynamic AFM. Phys. Rev. B 60, 11051–11061 (1999).

    CAS  Article  Google Scholar 

  22. Morse, R. W. & Bohm, H. V. Superconducting energy gap from ultrasonic attenuation measurements. Phys. Rev. 108, 1094–1096 (1957).

    CAS  Article  Google Scholar 

  23. Dzyaloshinskii, I. E., Lifshitz, E. M. & Pitaevskii, L. P. The general theory of van der Waals forces. Adv. Phys. 10, 165–209 (1961).

    Article  Google Scholar 

  24. Persson, B. N. J. Surface resistivity and vibrational damping in adsorbed layers. Phys. Rev. B 44, 3277–3296 (1991).

    CAS  Article  Google Scholar 

  25. Marot, L., De Temmerman, G., Thommen, V., Mathys, D. & Oelhafen, P. Characterization of magnetron sputtered rhodium films for reflective coatings. Surf. Coat. Tech. 202, 2837–2843 (2008).

    CAS  Article  Google Scholar 

  26. Gysin, U. et al. Rev. Sci. Instrum. (in the press).

  27. Nellen, P. M., Callegari, V. & Sennhauser, U. Preparative methods for nanoanalysis of materials with focused ion beam instruments. Chimia 60, 735–741 (2006).

    CAS  Article  Google Scholar 

  28. Rast, S. et al. Force microscopy experiments with ultrasensitive cantilevers. Nanotechnology 17, 189–194 (2006).

    Article  Google Scholar 

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We would like to thank Y. Pellmont for the technical support. This work was supported in part by the Swiss National Science Foundation, the ESF EUROCORE programme FANAS and by the NCCR Nanoscale Science of the Swiss National Science Foundation.

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The sample was fabricated by L.M. S.R. and U.G. constructed the system. The idea was born out of a discussion between E.M., M.K. and E.G. The measurement was carried out by M.K. E.M., M.K. and E.G. were involved in interpretation, discussion and paper writing.

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Correspondence to Marcin Kisiel.

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Kisiel, M., Gnecco, E., Gysin, U. et al. Suppression of electronic friction on Nb films in the superconducting state. Nature Mater 10, 119–122 (2011).

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