Thermal and quantum nucleation of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mrow /><mml:mn>4</mml:mn></mml:msup></mml:math>He crystals in aerogel

Matsuda, Hirofumi; Ochi, Aguri; Isozaki, R.; Masumoto, Ryota; Nomura, R.; Okuda, Y.

doi:10.1103/physreve.87.030401

Cited by 7 publications

(1 citation statement)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Crystallization of 4 He in aerogels shows a dynamical phase transition at around 600 mK which is the result of the competition between thermal fluctuation and spatial disorder: crystals grow via creep at high temperatures and via avalanche at low temperatures [13]. The creep and avalanche growth was clarified as the thermal activation and macroscopic quantum tunneling, respectively, from the crystallization rate and nucleation probability measurements [14,15]. In the quantum growth regime, the avalanche size distribution followed a power law, demonstrating the self-organized criticality at low temperatures where the quantum process governs the dynamics [14,16].…”

Section: Introductionmentioning

confidence: 99%

Formation of superfluid liquid pocket in aerogel and its solidification by cooling

Matsuda

Ochi

Isozaki

et al. 2013

Low Temperature Physics

Self Cite

View full text Add to dashboard Cite

Formation of superfluid liquid pockets of 4 He surrounded by 4 He crystals were observed in an aerogel of 96% porosity. The liquid pockets did not crystallize by application of pressure but crystallized via avalanche by cooling below a particular temperature. The crystallization by cooling was also observed when crystals occupied a smaller portion of the aerogel. Driving force for the crystallization by cooling and possible mass transport process are discussed.

show abstract

Section: Introductionmentioning

confidence: 99%

Formation of superfluid liquid pocket in aerogel and its solidification by cooling

Matsuda

Ochi

Isozaki

et al. 2013

Low Temperature Physics

Self Cite

View full text Add to dashboard Cite

show abstract

Fluctuating Surfaces of Growing 4He Crystals in Aerogel

et al. 2013

View full text Add to dashboard Cite

Crystallization ofHe4in aerogel via mass flow from surrounding solidHe4

et al. 2016

Self Cite

View full text Add to dashboard Cite

The phase boundary between the quantum solid and liquid phases of 4 He is strongly modified in a porous material. However the phase diagram at very low temperatures remains unexplored. We have used a variable-volume experimental cell with optical access to visualize the crystallization of 4 He in silica aerogels with independent control of the pressure and temperature. The onset of crystallization was investigated in two aerogel samples with differing porosity both by pressurization at constant temperature and by cooling at constant pressure. With isothermal pressurization we have established a low temperature phase diagram for each aerogel and we find that the equilibrium crystallization pressure is reduced with increasing aerogel porosity. Crystals also began to grow in the aerogel on cooling at fixed pressure below an onset temperature, Tgrow. We found that below this temperature the crystallization rate increased with decreasing temperature. The aerogel in our cell was surrounded by bulk crystals of 4 He and surprisingly Tgrow was found to be widely distributed when the surrounding bulk crystals were repressurized. In this experimental arrangement, crystallization within the aerogel on cooling requires mass flow from these exterior bulk crystals and is strongly influenced by the disordered structure at the interface between the bulk solid and the helium within the aerogel.

show abstract

Thermal and quantum nucleation of4He crystals in aerogel

Cited by 7 publications

References 30 publications

Formation of superfluid liquid pocket in aerogel and its solidification by cooling

Formation of superfluid liquid pocket in aerogel and its solidification by cooling

Fluctuating Surfaces of Growing 4He Crystals in Aerogel

Crystallization ofHe4in aerogel via mass flow from surrounding solidHe4

Contact Info

Product

Resources

About