Layer by layer solidification of {sup 4}He in narrow porous media

Journal Article · Mon Aug 01 04:00:00 EDT 2005 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PhysRevB.72.064516· OSTI ID:20719320

Rossi, M; Galli, D E; Reatto, L ^[1]

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1. Dipartimento di Fisica, Universita degli Studi di Milano, via Celoria 16, 20133 Milan (Italy)

We give a variational Monte Carlo description of {sup 4}He filling under pressure a porous material modeled by a smooth cylindrical nanopore. Our trial wave function is a shadow wave function which allows different degrees of correlation between {sup 4}He atoms depending on the distance from the pore wall but still preserving the full Bose symmetry. The radial density profile shows a strong layering of the {sup 4}He atoms which are located in concentric annuli. This system has a very rich phase diagram with at least four different phases. The layer in contact with the pore is always solid. For our narrow pore radius (R=13 A), as the density is increased, solidification takes place layer by layer, starting from the pore wall, as is confirmed by the static structure factors. The pore radius is too small to allow a bulklike solid to nucleate in the liquid region at the center of the pore, and in order to have a complete crystalline order in all the layers a pressure greater than 200 bar is needed. Computing the one body density matrix we are able to estimate the condensate fraction, which is still nonzero even if all the layers are in the solid phase.

• OSTI ID: 20719320
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 6 Vol. 72; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMS
BOSE-EINSTEIN CONDENSATION
CORRELATIONS
CRYSTAL STRUCTURE
DENSITY
DENSITY MATRIX
HELIUM
HELIUM 4
LAYERS
LIQUIDS
MONTE CARLO METHOD
NUCLEATION
PHASE DIAGRAMS
POROUS MATERIALS
SOLIDIFICATION
SOLIDS
STRUCTURE FACTORS
SYMMETRY
VARIATIONAL METHODS
WAVE FUNCTIONS