title: Observation of classical rotational inertia and nonclassical supersolid signals in solid 4He below 250 mK.
abstract: We have confirmed the existence, as first reported by Kim and Chan, of a supersolid state in solid 4He at temperatures below 250 mK. We have employed a torsional oscillator cell with a square cross section to insure a locking of the solid to the oscillating cell. We find that the nonclassical rotational inertia signal is not a universal property of solid 4He but can be eliminated through an annealing of the solid helium sample. This result has important implications for our understanding of the supersolid state.
authors.affiliation: Laboratory of Atomic and Solid State Physics and the Cornell Center for Materials Research, Cornell University, Ithaca, NY 14853-2501, USA.
authors.forename: Ann Sophie C
authors.initials: AS
authors.lastname: Rittner
authors.forename: John D
authors.initials: JD
authors.lastname: Reppy