Status of the Spurious Evidence for Photoinduced Superconductivity

After more than a decade of research on photoinduced superconductivity, the experimental evidence for its existence remains controversial. Recently, we identified a fundamental flaw in the analysis of several influential results on K$_3$C$_{60}$ and showed that similar measurements on other compounds suffer from the same problem. We described how to account for this systematic error, and reanalyzed evidence that had previously been advanced for both photoinduced superconductivity and Higgs-mediated terahertz amplification. We found that both phenomena may be understood instead as a photoenhancement of the carrier mobility that saturates with fluence, with no need to appeal to a photoinduced phase transition to a superconducting state. We summarize this reinterpretation and describe how subsequent work on K$_3$C$_{60}$ provides quantitative support for it.