Graphene bilayers reveal a reversible superfluid-to-supersolid transition in excitons

Physicists using two closely spaced graphene layers, a strong magnetic field, and ultracold temperatures observed bilayer excitons transition from a superfluid to an insulating, lattice-like state (interpreted as a supersolid) and then revert back to a superfluid, marking the first reported reversible superfluid-to-supersolid transition in this system in a Nature study led by Cory Dean and colleagues.