Observation of classical rotational inertia and nonclassical supersolid signals in solid 4He below 250 mK.

  title={Observation of classical rotational inertia and nonclassical supersolid signals in solid 4He below 250 mK.},
  author={Ann Sophie C. Rittner and John D. Reppy},
  journal={Physical review letters},
  volume={97 16},
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… Expand

Topics from this paper

The role of defects in Supersolid Helium-4
We seek an explanation for the observed non-classical rotational inertia in solid Helium-4. We study the activation energy for a single vacancy in an otherwise perfect crystal, which is huge andExpand
Measurements of Non-classical Rotational Inertia of Solid 4He at Two Frequencies
Abstract We have developed a double resonance compound torsional oscillator for studying non-classical rotational inertia (NCRI) of solid 4He at two different frequencies. The torsional oscillatorExpand
The Annealing Process in Solid 4He
Abstract We have used a torsional oscillator with square cross section and a resonance frequency of 185 Hz to confirm the nonclassical rotational inertia (NCRI) discovered by Kim and Chan (NatureExpand
Supersolidity and Disorder in Solid Helium 4
Abstract Supersolidity is a rather controversial issue which has been revived recently by a number of torsional oscillator (ac-rotation) experiments with solid helium 4. One possibility would be thatExpand
Search for superfluidity in solid hydrogen.
Evidence of a possible phase transition is found in solid para-hydrogen, marked by an abrupt increase in the resonant period of oscillation and onset of extremely long relaxation times as the temperature was raised above 60 mK. Expand
Search for supersolidity in solid 4He using multiple-mode torsional oscillators
Using multiple-frequency torsional oscillators, an experimental technique is used that enables the distinction between the effects of the shear modulus and those of a possible supersolid state, and separate frequency-dependent period shifts arising from changes in the elastic properties of the solid 4He from Possible supersolid signals, which are expected to be independent of frequency. Expand
Supersolidity and the Thermodynamics of Solid Helium
The specific heat of solid helium in the temperature range below about 1.2 K has been found to contain a term varying as T7, in addition to the usual T3 contribution always found in a crystallineExpand
On the Lattice Dynamics of Solid Helium and Supersolidity
In quest of a possible explanation of the recently revealed phenomena in solid 4He, which are ascribed to ‘supersolidity’, we reconsider the work of Nosanow and Shaw (Phys. Rev. 128:546, 1962) andExpand
Josephson effects in one-dimensional supersolids
We demonstrate that superflow past an obstacle is possible in a solid phase in the one-dimensional Gross-Pitaevskii equation with a finite-range two-body interaction. The phenomenon we find isExpand
Search for Supersolidity in 4He in Low-Frequency Sound Experiments
Abstract We present results of the search for supersolid 4He using low-frequency, low-level mechanical excitation of a solid sample grown and cooled at fixed volume. We have observed low frequencyExpand