Entropy of solid He4: the possible role of a dislocation glass

  title={Entropy of solid He4: the possible role of a dislocation glass},
  author={Alexander V. Balatsky and Matthias J. Graf and Zohar Nussinov and S. A. Trugman},
  journal={Physical Review B},
Solid He4 is viewed as a nearly perfect Debye solid. Yet, recent calorimetry indicates that its low-temperature specific heat has both cubic and linear contributions. These features appear in the same temperature range ($T \sim 200$ mK) where measurements of the torsional oscillator period suggest a supersolid transition. We analyze the specific heat to compare the measured with the estimated entropy for a proposed supersolid transition with 1% superfluid fraction. We find that the experimental… 
A Glassy Contribution to the Heat Capacity of hcp 4He Solids
We model the low-temperature specific heat of solid 4He in the hexagonal closed packed structure by invoking two-level tunneling states in addition to the usual phonon contribution of a Debye crystal
Possible high-temperature disorder-induced mobility of solid 4He at T ~ 1.8 K
Abstract It has been recently reported that there might be supersolidity of 4He around the temperature range: 1.3 K to 1.9 K [A. Eyal, O. Pelleg, L. Embon, E. Polturak, Phys. Rev. Lett. 105, 025301
Elementary Excitations in Solid and Liquid 4He at the Melting Pressure
Abstract Recent discovery of a nonclassical rotational inertia (NCRI) in solid 4He below 0.2 K by Kim and Chan has revived great interest in the problem of supersolidity and initiated intensive study
Defects and Glassy Dynamics in Solid 4He: Perspectives and Current Status
We review the anomalous behavior of solid 4He at low temperatures with particular attention to the role of structural defects present in solid. The discussion centers around the possible role of two
Formation of a disordered (Glassy) phase in deformed solid 4He in the region of supersolid state
A method has been proposed to create disorder in helium crystals by their deformation immediately during the experiment. Precise measurements of the pressure have been performed at a constant volume
Nearly frictionless transport of glassy solid helium at low temperature regime
Abstract Glassy matter, as subjected to high shear rates, exhibit shear-thinning: i.e., the viscosity diminishes with increasing shear rate. One possible outcome for almost vanishing viscosity is the
The role of glass dynamics in the anomaly of the dielectric function of solid helium
We propose that acousto-optical coupling of the electric field to strain fields around defects in disordered $^4$He is causing an increase of the dielectric function with decreasing temperature due
Interplay of Rotational, Relaxational, and Shear Dynamics in Solid 4He
Using a high-sensitivity torsional oscillator (TO) technique, the rotational and relaxational dynamics of solid helium-4 (4He) are mapped throughout the parameter range of the proposed supersolidity and it is demonstrated that the combined temperature-velocity dependence of the TO response is indistinguishable from the combinedTemperature-strain dependence ofThe solid’s shear modulus.
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) and
Absence of low-temperature anomaly on the melting curve of 4He
The melting pressure and pressure in the liquid at a constant density of ultrapure 4He (0.3 ppb of 3He impurities) have been measured with an accuracy of about 0.5 μbar in the temperature range from


Melting curve of 4He: no sign of a supersolid transition down to 10 mK.
Crystals of different quality show the expected T4 dependence in the range from 80 to 400 mK without any sign of the supersolid transition, and the coefficient is in excellent agreement with available data on the sound velocity in liquid 4He and on the Debye temperature of solid 4He.
The jamming route to the glass state in weakly perturbed granular media
Experimental evidence is reported for dynamic behaviour, qualitatively analogous to supercooling, in a driven granular system of macroscopic millimetre-size particles, based on similarities in the dynamical behaviour, rather than quantitative theory.
Elementary excitations and a collective mode in hcp4He
We have measured the velocity and attenuation of sound at 10, 30, and 50 MHz in solid4He at higher purity, lower density, and lower acoustic power than have been measured previously. At 10 MHz the
Tunneling states and the low-temperature thermal expansion of glasses
A recent theoretical model, based on tunneling states, for the heat capacity and thermal conductivity of amorphous solids below 1 K is extended to include thermal expansion. The calculated Grüneisen
Thermodynamics of an Incommensurate Quantum Crystal
It is shown that at low temperature T, the variation of the net vacancy concentration should be as T4 and that the first correction to the specific heat due to this varies as T7; these are quite consistent with experiments on solid helium-4.
Anomalous low-temperature thermal properties of glasses and spin glasses
Abstract We show that a linear specific heat at low temperatures for glass follows naturally from general considerations on the glassy state. From the same considerations we obtain the experimentally
Observation of Superflow in Solid Helium
We report on the observation of nonclassical rotational inertia in solid helium-4 confined to an annular channel in a sample cell under torsional motion, demonstrating superfluid behavior. The effect
Freezing and pressure-driven flow of solid helium in Vycor.
Measurements showed no indication of a mass redistribution in the Vycor that could mimic supersolid decoupling and put an upper limit of about 0.003 microm/s on any pressure-induced supersolid flow in the pores of VYcor.
Observation of classical rotational inertia and nonclassical supersolid signals in solid 4He below 250 mK.
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, which has important implications for the understanding of the supersolid state.
Specific Heat of Solid Helium
No HeadingRecent torsional oscillator measurements of solid 4He in Vycor glass suggest the existence of a supersolid state of matter below 175mK. We have obtained preliminary data of the specific