  Intense debate has recently arisen regarding the photoinduced changes to the
iron-chalcogenide superconductors, including the enhancement of
superconductivity and a metastable state. Here, by employing high energy
resolution, we directly observe the melting of superconductivity on ultrafast
timescales. We demonstrate a distinctly nonequilibrium response on short
timescales, where the gap fills in prior to the destruction of the
superconducting peak, followed by a metastable response. We propose that the
former is due to pair phase decoherence and speculate that the latter is due to
the increase in double stripe correlations that are known to compete with
superconductivity. Our results add to exciting new developments on the
iron-based superconductors, indicating that the photoinduced metastable state
possibly competes with superconductivity.
