Evidence for a Superglass State in Solid
            <sup>4</sup>
            He

Hunt, Benjamin; Pratt, Ethan; Gadagkar, Vikram; Yamashita, Minoru; Balatsky, Alexander V.; Davis, J. C.

doi:10.1126/science.1169512

Cited by 143 publications

(203 citation statements)

References 35 publications

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“…On the other hand, we found that the thermal conductivity is insensitive to the amplitude of oscillations. As was noted earlier [25,26], the dependences of the TO resonant frequency on amplitude V look basically identical to the temperature dependences Fig. 5), our exponent γ ≈ 0.71 is substantially different.…”

Section: Torsion Oscillations Resultssupporting

confidence: 86%

“…The logarithmic width of the cross-over, * * high low / T T is greater than unity and keeps increasing with increasing * T . Table 1 Driving a torsional oscillator at large amplitude is known to suppress the effect [10,25]; we confirm this. On the other hand, we found that the thermal conductivity is insensitive to the amplitude of oscillations.…”

Section: Torsion Oscillations Resultssupporting

confidence: 69%

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Thermal conductivity and torsional oscillations of solid 4He

Brazhnikov

Zmeev

Golov

2012

Low Temperature Physics

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Polycrystalline samples of hcp 4 He of molar volume V m = 19.5 cm 3 with small amount of 3 He impurities were grown in an annular container by the blocked-capillary method. Three concentrations of 3 He, x 3 , were studied: isotopically purified 4 He with the estimated x 3 < 10 -10 , commercial 'well-grade' helium with x 3 ~ 3⋅10 -7 and a mixture with x 3 = 2.5⋅10 -6. Torsional oscillations at two frequencies, 132.5 and 853.6 Hz, and thermal conductivity were investigated before and after annealing. The solid helium under investigation was located not only in the annular container but also in the axial fill line inside two torsion rods and dummy bob of the doublefrequency torsional oscillator. The analysis of the frequency shifts upon loading with helium and changing temperatures of different parts of the oscillator suggests that the three techniques probe the properties of solid helium in three different locations: the two different torsion modes respond to the changes of the shear modulus of solid helium in either of the two torsion rods while the thermal conductivity probes the phonon mean free path in solid helium inside the annular container. The temperature and width of the torsional anomaly increase with increasing frequency and x 3 . The phonon mean free path increases with increasing x 3 . Annealing typically resulted in an increased phonon mean free path but often in little change in the torsional oscillator response. While the magnitude of the torsional anomaly and phonon mean free path can be very different in different samples, no correlation was found between them. PACS: 67.80.bd Superfluidity in solid 4 He, supersolid 4 He; 65.40.-b Thermal properties of crystalline solids.

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Section: Torsion Oscillations Resultssupporting

confidence: 86%

Section: Torsion Oscillations Resultssupporting

confidence: 69%

Thermal conductivity and torsional oscillations of solid 4He

Brazhnikov

Zmeev

Golov

2012

Low Temperature Physics

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“…Indeed, later numerical results point towards such a possibility. 22 Notably, recent experimental results 13 agree with an earlier suggested theory concerning such transient dynamics. 14 The presence of non-uniformity in 4 He is also suggested by a criterion comparing the change in dissipation vs. relative period shift in torsion oscillator.…”

Section: Introductionsupporting

confidence: 82%

“…12 Relaxational dynamics in torsional oscillators has also been reported by the Cornell group of Davis. 13 The torsional oscillator findings can arise from material characteristics alone. [14][15][16][17][18][19][20][21] In particular, the thermodynamics and transient dynamics of distributed processes in amorphous or general non-equilibrated solids can currently fit 9,14 observed results.…”

Section: Introductionmentioning

confidence: 99%

Influence of elastic deformations on the supersolid transition

et al. 2011

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We study within the Ginzburg-Landau (GL) theory of phase transitions how elastic deformations in a supersolid lead to local changes in the supersolid transition temperature. The GL theory is mapped onto a Schrödinger-type equation with an effective potential that depends on local dilatory strain. The effective potential is attractive for local contraction and repulsive for local expansion. Different types of elastic deformations are studied. We find that a contraction (expansion) of the medium that may be brought about by either externally applied or internal strain leads to a higher (lower) transition temperature as compared to the unstrained medium. In addition, we investigate edge dislocations and illustrate that the local transition temperature may be increased in the immediate vicinity of the dislocation core. Our analysis is not limited to supersolidity. Similar strain effects should also play a role in superconductors.

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“…The structure of these two theories is markedly different, suggesting the possibility of non-trivial emergent physics over the full range of parameters that tune between the classical and quantum limits. Although this formulation makes no explicit mention of particle statistics, such an extension is possible, enabling treatment of purported glass formation in systems with a finite superfluid fraction [7][8][9] .The fully microscopic QMCT allows for a detailed description of the dynamical phase diagram that separates an ergodic fluid region from an arrested glassy one as a function of both thermodynamic control variables and the parameters (for exampleh) that control the size of quantum fluctuations. To illustrate this, we carry out detailed QMCT calculations on a hard-sphere system as a function of the system's volume fraction φ and the dimensionless parameter Λ * , which is the ratio of the de Broglie thermal wavelength to the particle size and controls the scale of quantum behaviour.…”

mentioning

confidence: 99%

Quantum fluctuations can promote or inhibit glass formation

et al. 2011

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Glasses are dynamically arrested states of matter that do not exhibit the long-range periodic structure of crystals 1-4 . Here we develop new insights from theory and simulation into the impact of quantum fluctuations on glass formation. As intuition may suggest, we observe that large quantum fluctuations serve to inhibit glass formation as tunnelling and zero-point energy allow particles to traverse barriers facilitating movement. However, as the classical limit is approached a regime is observed in which quantum effects slow down relaxation making the quantum system more glassy than the classical system. This dynamical 'reentrance' occurs in the absence of obvious structural changes and has no counterpart in the phenomenology of classical glass-forming systems.Although a wide variety of glassy systems ranging from metallic to colloidal can be accurately described using classical theory, quantum systems ranging from molecular, to electronic and magnetic form glassy states 5,6 . Perhaps the most intriguing of these is the coexistence of superfluidity and dynamical arrest, namely the 'superglass' state suggested by recent numerical, theoretical and experimental work [7][8][9] . Although such intriguing examples exist, at present there is no unifying framework to treat the interplay between quantum and glassy fluctuations in the liquid state.To attempt to formulate a theory for a quantum liquid to glass transition, we may first appeal to the classical case for guidance. Here, a microscopic theory exists in the form of mode-coupling theory (MCT), which requires only simple static structural information as input and produces a full range of dynamical predictions for time correlation functions associated with single-particle and collective fluctuations 10 . Although MCT has a propensity to overestimate a liquid's tendency to form a glass, it has been shown to account for the emergence of the non-trivial growing dynamical length scales associated with vitrification 11 . Perhaps more importantly, MCT has made numerous non-trivial predictions ranging from logarithmic temporal decay of density fluctuations and reentrant dynamics in adhesive colloidal systems to various predictions concerning the effect of compositional mixing on glassy behaviour 12,13 . These have been confirmed by both simulation and experiment [14][15][16] .A fully microscopic quantum version of MCT (QMCT) that requires only the observable static structure factor as input may be developed along the same lines as the classical version. Indeed, a zero-temperature version of such a theory has been developed and successfully describes the wave-vector-dependent dispersion in superfluid helium 17 . In the Supplementary Information, we outline the derivation of a full temperature-dependent QMCT. In the limit of high temperatures, our theory reduces to the hard-sphere fluid. φ is the volume fraction, Λ * = (βh 2 /mσ 2 ) 1/2 is the thermal wavelength in units of inter-particle separation σ , and β = 1/k B T is the inverse temperature. The approach by which the...

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Evidence for a Superglass State in Solid ⁴ He

Cited by 143 publications

References 35 publications

Thermal conductivity and torsional oscillations of solid 4He

Thermal conductivity and torsional oscillations of solid 4He

Influence of elastic deformations on the supersolid transition

Quantum fluctuations can promote or inhibit glass formation

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Evidence for a Superglass State in Solid 4 He

Cited by 143 publications

References 35 publications

Thermal conductivity and torsional oscillations of solid 4He

Thermal conductivity and torsional oscillations of solid 4He

Influence of elastic deformations on the supersolid transition

Quantum fluctuations can promote or inhibit glass formation

Contact Info

Product

Resources

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Evidence for a Superglass State in Solid ⁴ He