Influence of Deformation on the Formation of a Glassy Phase of 4He in the Supersolid Region

Rudavskiı̆, É. Ya.; Grigor’ev, V. N.; Lisunov, A. A.; Maı̆danov, V. A.; Rubanskii, V. Yu.; Rubets, S. P.; Rybalko, A. S.; Tikhii, V. A.

doi:10.1007/s10909-009-9996-6

Cited by 11 publications

(3 citation statements)

References 9 publications

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“…Since a true phase transition is a bulk effect of the sample, we investigated previously thermodynamic signatures as reported by specific heat and pressure measurements. 31,32,33,34,35 Our thermodynamic analysis in terms of two-level systems is consistent with a glassy interpretation of the linear-T dependence in the specific heat below ∼ 100 mK and the quadratic-T dependence in pressure measurements of the equation of state, P(T ), of an otherwise perfect Debye solid. 16,36 A Debye solid exhibits a specific heat C ∝ T 3 and a pressure dependence P ∝ T 4 .…”

Section: Introductionsupporting

confidence: 79%

The Glassy Response of Double Torsion Oscillators in Solid 4He

Graf

Dahal

et al. 2010

J Low Temp Phys

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Single and double torsion oscillators have been used to measure the anomalous change in resonant frequency and accompanying dissipation in solid 4 He. We present a glass description of the mechanical anomalies found in torsion oscillator measurements. Our results show that it is not necessary to invoke a supersolid interpretation to explain these mechanical anomalies. Previously, we demonstrated that the back-action of a glassy subsystem present in solid 4 He can account for frequency change and dissipation peak in single torsion oscillator experiments. Here, we show that the same glassy back-action can explain the experimental results of the composite torsion oscillator developed by the Rutgers group, which measures the response of solid 4 He at the in-phase mode f 1 = 496 Hz and out-of-phase mode f 2 = 1173 Hz. IntroductionThe controversy over the origin of the anomalous low-temperature signature in solid 4 He continues since it was first discovered in ultrasound measurements by Goodkind and collaborators 1,2,3 and eventually detected in torsion oscillator (TO) experiments by Kim and Chan. 4,5 In earlier work, we argued that the origin of the TO anomaly is not that of a non-classical rotational inertia effect (NCRI), but rather due to a mechanical effect. We examined the response of a nonuniform solid

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Section: Introductionsupporting

confidence: 79%

The Glassy Response of Double Torsion Oscillators in Solid 4He

Graf

Dahal

et al. 2010

J Low Temp Phys

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“…Coalescence of vacancies into vacancy discs which are so-called Frank loops [26] (Frank's partial dislocations [80]) is another channel to relax the internal stresses and external pressure in the crystal. The role of the vacancies in thermodynamics of helium crystals is a matter of discussions for a long time [20][21][22][23][24], but at present the problem remains still unsolved.…”

Section: Thermodynamics Of Dilutementioning

confidence: 99%

“…It is remarkable that both the thermodynamical [1,3] and mechanical (acoustical) anomalies appear just below 0.25 K, and this fact most likely suggests that they are phenomena of the common nature. For this moment it is agreed that all the relevant observations are results of some structural disorder created by crystal lattice defects (dislocations [6,11,[15][16][17][18][19] or vacancies [20][21][22][23][24]).…”

Section: Introductionmentioning

confidence: 99%

Thermodynamics of dilute 3He–4He solid solutions with hcp structure

Chishko

2018

Low Temperature Physics

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To interpret the anomalies in heat capacity C V (T) and temperature-dependent pressure P(T) of solid hexagonal close-packed (hcp)4He we exploit the model of hcp crystalline polytype with specific lattice degrees of freedom and describe the thermodynamics of impurity-free 4 He solid as superposition of phononic and polytypic contributions. The hcp-based polytype is a stack of 2D basal atomic monolayers on triangular lattice packed with arbitrary long (up to infinity) spatial period along the hexagonal c axis perpendicular to the basal planes. It is a crystal with perfect ordering along the layers, but without microscopic translational symmetry in perpendicular direction (which remains, nevertheless, the rotational crystallographic axis of third order, so that the polytype can be considered as semidisordered system). Each atom of the hcp polytype has twelve crystallographic neighbors in both first and second coordination spheres at any arbitrary packing order. It is shown that the crystal of such structure behaves as anisotropic elastic medium with specific dispersion law of phonon excitations along c axis. The free energy and the heat capacity consist of two terms: one of them is a normal contribution (with C V (T)  T 3 ) from phonon excitations in an anisotropic lattice of hexagonal symmetry, and another term (an "excessive" heat) is a contribution resulted by packing entropy from quasi-one-dimensional system of 2D basal planes on triangular lattice stacked randomly along c axis without braking the closest pack between neighboring atomic layers. The excessive part of the free energy has been treated within 1D quasi-Ising (lattice gas) model using the transfer matrix approach. This model makes us possible to interpret successfully the thermodynamic anomaly (heat capacity peak in hcp 4 He) observed experimentally.

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On the Lattice Dynamics of Solid Helium and Supersolidity

Krainyukova

2010

J Low Temp Phys

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Influence of Deformation on the Formation of a Glassy Phase of 4He in the Supersolid Region

Cited by 11 publications

References 9 publications

The Glassy Response of Double Torsion Oscillators in Solid 4He

The Glassy Response of Double Torsion Oscillators in Solid 4He

Thermodynamics of dilute 3He–4He solid solutions with hcp structure

On the Lattice Dynamics of Solid Helium and Supersolidity

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