Evidence for a Superglass State in Solid 4He

Abstract

Although solid helium-4 (4He) may be a supersolid it also exhibits many phenomena unexpected in that context. We studied relaxation dynamics in the resonance frequency f(T) and dissipation D(T) of a torsional oscillator containing solid 4He. With the appearance of the "supersolid" state, the relaxation times within f(T) and D(T) began to increase rapidly together. More importantly, the relaxation processes in both D(T) and a component of f(T) exhibited a complex synchronized ultraslow evolution towards equilibrium. Analysis using a generalized rotational susceptibility revealed that, while exhibiting these apparently glassy dynamics, the phenomena were quantitatively inconsistent with a simple excitation freeze-out transition because the variation in f was far too large. One possibility is that amorphous solid 4He represents a new form of supersolid in which dynamical excitations within the solid control the superfluid phase stiffness.

25 pages (12 main manuscript, 13 supporting material), 10 figures (4 main manuscript, 6 supporting material)

References in corpus (12)

• Low Temperature Shear Modulus Changes in Solid 4-He and Connection to Supersolidity
• Oscillation Frequency Dependence of Non-Classical Rotation Inertia of Solid ${}^4$He
• Observation of Unusual Mass Transport in Solid hcp 4He
• Observation of non-classical rotational inertia in bulk solid 4He
• Annealing Effect for Supersolid Fraction in ${}^4$He
• Nonclassical Rotational Inertia in Single Crystal Helium
• On the origin of the decrease in the torsional oscillator period of solid He4
• The effect of 3He impurities on the nonclassical response to oscillation of solid 4He
• Probing the Upper Limit of Nonclassical Rotational Inertia
• Theory of the superglass phase
• Thermal History of Solid 4He Under Oscillation
• New Dissipation Relaxation Phenomenon in Oscillating Solid He-4

Cited by in corpus (8)

• Atom-light crystallization of BECs in multimode cavities: Nonequilibrium classical and quantum phase transitions, emergent lattices, supersolidity, and frustration
• Non-linear Elastic Response in Solid Helium: critical velocity or strain
• Interplay of Rotational, Relaxational, and Shear Dynamics in Solid 4He
• Evidence for a High-Temperature Disorder-Induced Mobility in Solid ${}^4$He
• A glassy contribution to the heat capacity of hcp ${}^4$He solids
• Leggett's bound for amorphous solids
• The glassy response of double torsion oscillators in solid Helium-4
• On The Mobile Behavior of Solid ${}^4$He at High Temperatures