Simultaneous investigation of shear modulus and torsional resonance of solid 4He

Abstract

We investigate the origin of a resonant period drop of a torsional oscillator (TO) containing solid ${}^4$He by inspecting its relation to a change in elastic modulus. To understand this relationship directly, we measure both phenomena simultaneously using a TO with a pair of concentric piezoelectric transducers inserted in its annulus. Although the temperature, ${}^3$He concentration, and frequency dependence are essentially the same, a marked discrepancy in the drive amplitude dependence is observed. We find that this discrepancy originates from the anisotropic response of polycrystalline solid ${}^4$He connected with low-angle grain boundaries by studying the shear modulus parallel to and perpendicular to the driving direction.

References in corpus (20)

• Low Temperature Shear Modulus Changes in Solid 4-He and Connection to Supersolidity
• Absence of supersolidity in solid helium in porous Vycor glass
• Disorder and the Supersolid State of Solid ${}^4$He
• Oscillation Frequency Dependence of Non-Classical Rotation Inertia of Solid ${}^4$He
• Evidence for a Superglass State in Solid 4He
• The giant plasticity of a quantum crystal
• Nonclassical Rotational Inertia in Single Crystal Helium
• Intrinsic and dislocation induced elastic behavior of solid helium
• The effect of 3He impurities on the nonclassical response to oscillation of solid 4He
• Probing the Upper Limit of Nonclassical Rotational Inertia
• Vortex Fluid State below an Onset Temperature T_0 of Solid 4He
• Non-linear Elastic Response in Solid Helium: critical velocity or strain
• Dislocation networks in helium-4 crystals
• Critical dislocation speed in helium-4 crystals
• Upper limit of supersoldity in solid helium
• Interpreting Torsional Oscillator Measurements: Effect of Shear Modulus and Supersolidity
• Simultaneous Measurements of the Torsional Oscillator Anomaly and Thermal Conductivity in Solid 4He
• Supersolid behavior in confined geometry
• Frequency-dependent Study of Solid Helium-4 Contained in a Rigid Double-torus Torsional Oscillator
• In Pursuit of the Elusive Supersolid

Cited by in corpus (2)

• Simulation and understanding of quantum crystals
• Superfluid-like TO Responses in Rotating Solid Helium