Photons that aren't actually there influence superconductivity
Despite the headline, this isn't really a story about superconductivity—at least not the superconductivity that people care about, the stuff that doesn't require exotic refrigeration to work. Instead, it's a story about how superconductivity can be used as a test of some of the weirder consequences of quantum mechanics, one that involves non-existent particles of light that still act like they exist.
Researchers have found a way to get these virtual photons to influence the behavior of a superconductor, ultimately making it worse. That may in the end tell us something useful about superconductivity, but it'll probably take a little while.
Virtual reality
The story starts with quantum field theory, which is incredibly complex, but the simplified version is that even empty space is filled with fields that could govern the interactions of any quantum objects in or near that space. You can think of different particles as energetic excitements of these fields—so a photon is simply an energetic state of the quantum field.