Possible light-induced superconductivity in K3C60 at high temperature

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The non-equilibrium control of emergent phenomena in solids is an important research frontier, encompassing effects such as the optical enhancement of superconductivity1. Nonlinear excitation2,3 of certain phonons in bilayer copper oxides was recently shown to induce superconducting-like optical properties at temperatures far greater than the superconducting transition temperature, Tc (refs 4, 5, 6). This effect was accompanied by the disruption of competing charge-density-wave correlations7,8, which explained some but not all of the experimental results. Here we report a similar phenomenon in a very different compound, K3C60. By exciting metallic K3C60 with mid-infrared optical pulses, we induce a large increase in carrier mobility, accompanied by the opening of a gap in the optical conductivity. These same signatures are observed at equilibrium when cooling metallic K3C60 below Tc (20 kelvin). Although optical techniques alone cannot unequivocally identify non-equilibrium high-temperature superconductivity, we propose this as a possible explanation of our results.

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Change history

  • Corrected online 24 February 2016

    The final sentence of the Fig. 4 legend was inadvertently truncated in the PDF of the AOP version, but has now been corrected.


  1. 1.

    et al. Light-induced superconductivity in a stripe-ordered cuprate. Science 331, 189–191 (2011)

  2. 2.

    et al. Nonlinear lattice dynamics as a basis for enhanced superconductivity in YBa2Cu3O6.5. Nature 516, 71–73 (2014)

  3. 3.

    et al. Coherent modulation of the YBa2Cu3O6+x atomic structure by displacive stimulated ionic Raman scattering. Phys. Rev. B 91, 094308 (2015)

  4. 4.

    et al. Optically-induced coherent transport far above Tc in underdoped YBa2Cu3O6+δ. Phys. Rev. B 89, 184516 (2014)

  5. 5.

    et al. Optically enhanced coherent transport in YBa2Cu3O6.5 by ultrafast redistribution of interlayer coupling. Nature Mater . 13, 705–711 (2014)

  6. 6.

    et al. Two distinct kinetic regimes in the relaxation of light induced superconductivity in La1.675Eu0.2Sr0.125CuO4. Phys. Rev. B 91, 020505 (2015)

  7. 7.

    et al. Melting of charge stripes in vibrationally driven La1.875Ba0.125CuO4: assessing the respective roles of electronic and lattice order in frustrated superconductors. Phys. Rev. Lett. 112, 157002 (2014)

  8. 8.

    et al. Femtosecond X-rays link melting of charge density wave correlations and light enhanced coherent transport in YBa2Cu3O6.6. Phys. Rev. B 90, 184514 (2014)

  9. 9.

    Alkali-doped Fullerides: Narrow-band Solids with Unusual Properties (World Scientific, 2004)

  10. 10.

    et al. Superconductivity at 18 K in potassium-doped C60. Nature 350, 600–601 (1991)

  11. 11.

    et al. Synthesis and electronic transport of single crystal K3C60. Science 256, 1190–1191 (1992)

  12. 12.

    , & Electronic correlation effects and superconductivity in doped fullerenes. Science 254, 970–974 (1991)

  13. 13.

    et al. Strongly correlated superconductivity. Science 296, 2364–2366 (2002)

  14. 14.

    , & Superconductivity in the fullerenes. Science 254, 989–992 (1991)

  15. 15.

    et al. Electron-phonon coupling and superconductivity in alkali-intercalated C60 solid. Phys. Rev. Lett. 68, 526–529 (1992)

  16. 16.

    , & Strong superconductivity with local Jahn Teller phonons in C60 solids. Phys. Rev. Lett. 90, 167006 (2003)

  17. 17.

    et al. Optical properties of the alkali-metal-doped superconducting fullerenes: K3C60 and Rb3C60. Phys. Rev. B 49, 7012–7025 (1994)

  18. 18.

    et al. Optical measurements of the superconducting gap in single-crystal K3C60 and Rb3C60. Nature 369, 541–543 (1994)

  19. 19.

    The complete excitation spectrum of the alkali-metal-doped superconducting fullerenes. Mod. Phys. Lett. B 9, 445–468 (1995)

  20. 20.

    & Charged-phonon absorption in doped C60. Phys. Rev. B 45, 10173–10176 (1992)

  21. 21.

    et al. Optical conductivity of BCS superconductors with arbitrary purity. Physica C 183, 99–104 (1991)

  22. 22.

    et al. Nonlinear phononics as a new ultrafast route to lattice control. Nature Phys . 7, 854–856 (2011)

  23. 23.

    , & Theory of nonlinear phononics for coherent light control of solids. Phys. Rev. B 89, 220301(R) (2014)

  24. 24.

    et al. Optical properties of a vibrationally modulated solid state Mott insulator. Sci. Rep. 4, 3823 (2014)

  25. 25.

    et al. THz-frequency modulation of the Hubbard U in an organic Mott insulator. Phys. Rev. Lett. 115, 187401 (2015)

  26. 26.

    et al. Structure of single-phase superconducting K3C60. Nature 351, 632–634 (1991)

  27. 27.

    et al. Performance of SISSI, the infrared beamline of the ELETTRA storage ring. J. Opt. Soc. Am. B 24, 959–964 (2007)

  28. 28.

    & On the Robinson and Price (Kramers-Kronig) method of interpreting reflection data taken through a transparent window. J. Chem. Phys. 38, 612–617 (1963)

  29. 29.

    et al. Dynamics of spectral hole burning. IEEE J. Quantum Electron. 24, 261–269 (1988)

  30. 30.

    & Terahertz time-domain spectroscopy of transient metallic and superconducting states. Phys. Rev. B 92, 134507 (2015)

  31. 31.

    , & Subpicosecond carrier dynamics in low-temperature grown GaAs as measured by time-resolved terahertz spectroscopy. J. Appl. Phys. 90, 5915–5923 (2001)

  32. 32.

    , Mitrano, M., Cantaluppi, A. & Cavalleri, A. Comment on “Terahertz time-domain spectroscopy of transient metallic and superconducting states” (arXiv:1506.06758). Preprint at (2015)

  33. 33.

    & Optical study of electronic structures and phonons in alkali-metal-doped C60. Phys. Rev. B 51, 3678–3685 (1995)

  34. 34.

    et al. Gate tunable infrared phonon anomalies in bilayer graphene. Phys. Rev. Lett. 103, 116804 (2009)

  35. 35.

    & Efficient iterative schemes for ab initio total energy calculations using a plane-wave basis set. Phys. Rev. B 54, 11169–11186 (1996)

  36. 36.

    , & First-principles calculations of the ferroelastic transition between rutile-type and CaCl2-type SiO2 at high pressures. Phys. Rev. B 78, 134106 (2008)

  37. 37.

    et al. QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials. J. Phys. Condens. Matter 21, 395502 (2009)

  38. 38.

    , & Analytical molecular orbitals and band structures of solid C60. Phys. Rev. B 51, 17446–17478 (1995)

  39. 39.

    , & A complete nearest-neighbor force field model for C60. J. Chem. Phys. 120, 6912–6921 (2004)

  40. 40.

    , & Coulomb integrals and model Hamiltonians for C60. Phys. Rev. B 46, 13647–13650 (1992)

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We acknowledge S. Kivelson and A. Georges for discussion. We are also grateful to A. Subedi for sharing microscopic calculations of anharmonic mode coupling. We thank L. Degiorgi for sharing optical data measured on single crystals. Technical support during sample handling was provided by H.-P. Liermann and M. Wendt. We additionally acknowledge support from M. Gaboardi (for SQUID magnetometry) and from J. Harms (for graphics). The research leading to these results received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013)/ERC Grant Agreement no. 319286 (QMAC). We acknowledge support from the Deutsche Forschungsgemeinschaft via the excellence cluster ‘The Hamburg Centre for Ultrafast Imaging — Structure, Dynamics and Control of Matter at the Atomic Scale’ and the priority program SFB925. This work was also supported by the Swiss National Supercomputing Center (CSCS) under the project ID s497.

Author information


  1. Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany

    • M. Mitrano
    • , A. Cantaluppi
    • , D. Nicoletti
    • , S. Kaiser
    • , S. R. Clark
    •  & A. Cavalleri
  2. The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany

    • A. Cantaluppi
    • , D. Nicoletti
    •  & A. Cavalleri
  3. INSTM UdR Trieste-ST and Elettra–Sincrotrone Trieste S.C.p.A., Area Science Park, 34012 Basovizza, Trieste, Italy

    • A. Perucchi
    •  & P. Di Pietro
  4. CNR-IOM and Dipartimento di Fisica, Università di Roma “Sapienza”, Piazzale A. Moro 2, 00185 Roma, Italy

    • S. Lupi
  5. Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Parma, Parco Area delle Scienze, 7/a, 43124 Parma, Italy

    • D. Pontiroli
    •  & M. Riccò
  6. Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY, UK

    • S. R. Clark
  7. Department of Physics, Oxford University, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UK

    • S. R. Clark
    • , D. Jaksch
    •  & A. Cavalleri
  8. Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore

    • D. Jaksch


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A. Cavalleri conceived the project and the experiments together with M.M. and S.K. The time-resolved THz set-up was built by M.M. and A. Cantaluppi, who performed the pump–probe measurements and analysed the data with support from D.N. and S.K. Equilibrium optical properties were measured and analysed by M.M. and A. Cantaluppi, with support from A.P., S.L. and P.D.P. Samples were grown and characterized by D.P. and M.R. S.R.C. and D.J. provided calculations of time-dependent on-site correlation energies. The manuscript was written by A. Cavalleri, D.N. and M.M., with input from all authors.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to A. Cavalleri.

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