Shining lasers at superconductors can make them work at higher temperatures, suggests new findings from an international team of scientists including the University of Bath.
Superconductors are materials that conduct electricity without power loss and produce strong magnetic fields. They are used in medical scanners, super-fast electronic circuits and in Maglev trains which use superconducting magnets to make the train hover above the tracks, eliminating friction.
Ref: Possible light-induced superconductivity in K3C60 at high temperature. Nature (8 February 2016) | DOI: 10.1038/nature16522
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 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. This effect was accompanied by the disruption of competing charge-density-wave correlations, 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.