A Glassy State of Supersolid Helium

摘要

Superfluid helium is best known for its ability to flow without resistance. Superfluids also differ from ordinary fluids in that they fail to respond to a slow steady rotation (1). The atoms in a superfluid are in the same quantum state, so they move coherently and cannot gradually "spin up," as does water in a rotated container. An intriguing question is whether a supersolid-formed by applying pressure to a superfluid-could combine these remarkable properties, quantum coherence and dissipationless mass flow of atoms, in a solid that still has structural order and rigidity (1-4).