The discoveries stem from a recent revolution in materials science: All three new instances of superconductivity arise in devices assembled from flat sheets of atoms. These materials display unprecedented flexibility; at the touch of a button, physicists can switch them between conducting, insulating, and more exotic behaviors—a modern form of alchemy that has supercharged the hunt for superconductivity.
It now seems increasingly likely that diverse causes can give rise to the phenomenon. Just as birds, bees and dragonflies all fly using different wing structures, materials seem to pair electrons together in different ways. Even as researchers debate exactly what’s happening in the various two-dimensional materials in question, they anticipate that the growing zoo of superconductors will help them achieve a more universal view of the alluring phenomenon.
What's really cool is that unlike with conventional 3d superconductors, these layered materials give one much more control over doping levels. A back gate is all it takes, while in the past one had to prepare a whole new sample to change the number of electrons in the sample.