Abstract-Possible light-induced superconductivity in K3C60 at high temperature

• M. Mitrano,
• A. Cantaluppi,
• D. Nicoletti,
• S. Kaiser,
• A. Perucchi,
• S. Lupi,
• P. Di Pietro,
• D. Pontiroli,
• M. Riccò,
• S. R. Clark,
• D. Jaksch
• & A. Cavalleri

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature16522.html

The non-equilibrium control of emergent phenomena in solids is an important research frontier, encompassing effects such as the optical enhancement of superconductivity¹. Nonlinear excitation^2, 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 correlations^7, 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.