The Mystery of Two Gaps in a New Superconductor express
Electrons in a crystal sometimes behave like a stadium crowd doing the wave: areas of higher density alternate with nearly empty ones. This wave blocks the free flow of charges — under normal conditions, the material is not superconducting. But apply pressure, and the wave vanishes, letting electrons move without resistance. Ultrashort laser flashes (a method of optical spectroscopy with precise light measurements) allowed a peek into the wave's structure. It turned out that breaking the wave requires overcoming two energy steps—54 and 67 millielectronvolts. Like a lock needing two differently shaped keys. At helium temperatures, when thermal jitters almost fade, the crystal's own vibrations, phonons, become audible. Their dance adapts to the electron wave, altering the system's overall disorder. The ideas of John Bardeen on electron pairing and Lev Landau on electron liquids intertwine here into a single mechanism.
With superconductivity, current can flow in a closed loop forever without a power source: that's used in MRI scanners.
In the sci-fi movie Avatar, the mineral unobtanium is a superconductor that floats in a magnetic field. Real layered materials bring that fantasy a little closer.