Superfluid Fraction of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>H</mml:mi></mml:mrow><mml:mprescripts /><mml:mrow /><mml:mrow><mml:mn>3</mml:mn></mml:mrow><mml:mrow /><mml:mrow /></mml:mmultiscripts></mml:mrow><mml:mi>e</mml:mi><mml:mi>−</mml:mi><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>H</mml:mi></mml:mrow><mml:mprescripts /><mml:mrow /><mml:mrow><mml:mn>4</mml:mn></mml:mrow><mml:mrow /><mml:mrow /></mml:mmultiscripts></mm

Kimball, Mark O.; Gasparini, Francis M.

doi:10.1103/physrevlett.86.1558

Cited by 17 publications

(5 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[51,52]. On the other hand, more recent experiments [55,56] on 4 He films with thicker films seem to match less well. We have also computed the universal amplitude ratio [L 0,KT /ξ 2nd ] * = 3.864(9), where ξ 2nd is the second moment correlation length of the three-dimensional bulk system in the high temperature phase.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

The Kosterlitz–Thouless transition in thin films: a Monte Carlo study of three-dimensional lattice models

Hasenbusch¹

2009

J. Stat. Mech.

View full text Add to dashboard Cite

We study the phase transition of thin films in the three-dimensional XY universality class. To this end, we perform a Monte Carlo study of the improved two-component φ 4 model, the improved dynamically diluted XY model and the standard XY model on the simple cubic lattice. We study films of a thickness up to L 0 = 32 lattice spacings. In the short direction of the lattice free boundary conditions are employed. Using a finite size scaling (FSS) method, proposed recently, we determine the transition temperature with high accuracy. The effectively two-dimensional finite size scaling behaviour of the Binder cumulant U 4 , the second moment correlation length over the lattice size ξ 2nd /L, the ratio of the partition functions with antiperiodic and periodic boundary conditions Z a /Z p and the helicity modulus Υ clearly confirm the Kosterlitz-Thouless nature of the transition. We analyse the scaling of the transition temperature with the thickness L 0 of the film. The predictions of the renormalization group (RG) theory are confirmed. We compute the universal ratio of the thickness of the film L 0 and the transversal correlation length ξ T in the three-dimensional thermodynamic limit at the Kosterlitz-Thouless transition temperature of a film of thickness L 0 : [L 0,KT /ξ T ] * = 1.595 (7). This results can be compared with experimental results on thin films of 4 He near the λ-transition.

show abstract

Section: Discussionmentioning

confidence: 99%

“…In refs. [55,56] the KT temperature has been determined for films of the thickness 483 Å and 2113 Å at saturated vapour pressure. These films are confined by two wafers of silicon.…”

Section: The Helicity Modulus In the Low Temperature Phasementioning

confidence: 99%

The Kosterlitz–Thouless transition in thin films: a Monte Carlo study of three-dimensional lattice models

Hasenbusch¹

2009

J. Stat. Mech.

View full text Add to dashboard Cite

show abstract

“…Two sets of data are plotted here. The open circles are for a uniform film 48.3 nm thick 25 , and the filled circles are for the 31.7 nm film in the presence of the (2 µm) 3 boxes. The behaviour of the bulk ρ s /ρ is indicated as a solid line 26 .…”

Section: Figure 1 | the Confinement Cellmentioning

confidence: 99%

Coupling and proximity effects in the superfluid transition in 4He dots

et al. 2010

Self Cite

View full text Add to dashboard Cite

The superfluid transition in 4 He is associated with the onset of an order parameter that is a macroscopic wavefunction. This is similar to the onset of superconductivity in metals and alloys. Yet, some of the hallmark phenomena that are associated with wavefunctions, and are evident in superconductors, have not been identified in 4 He. Here we report proximity effects on the specific heat and superfluid density of a thin 4 He film in equilibrium with an array of larger boxes of 4 He. Comparison with previous data also enables us, by scaling, to deduce an excess specific heat associated with a collective behaviour of weakly coupled boxes. These effects should be relevant to the understanding of experiments where helium has been studied when confined in packed powders, porous materials or other inhomogeneous confinements, where proximity and collective effects must be present but not readily quantifiable 1,2 . Our work also forms a point of comparison and contrast with the case of superconductors 3,4 , and is relevant to studies of Josephson effects in superfluids, coupling effects in arrays of Bose-condensed atoms 5,6 , and magnetic systems where, because of chemical composition, two separate but interacting ordering transitions take place 7,8 .In the case of superconductors, coupling and proximity effects have been well understood for many years. The large correlationlength amplitude ξ 0 makes coupling between two superconductors easy to achieve. Weak links with dimensions of the order of ξ 0 , which can be a metal, an insulator or another superconductor, enable measurements of the familiar Josephson effects (see for instance ref. 9). With 4 He these effects are much more difficult to achieve because ξ 0 is of the order of interatomic dimensions. Furthermore, weak links and coupling between two regions of 4 He cannot be achieved through any material other than 4 He. We can, however, take advantage of the growth of the correlation length with temperature T and critical exponent ν, ξ = ξ 0 |1 − T /T λ | −ν ≡ ξ 0 t −ν near the transition temperature T λ and construct apertures whereby analogous Josephson effects can be realized 10,11 .We are unaware of any theory that describes the effects on thermodynamic properties of a 'grain' or dot of helium due to a coupling to another dot through a weak link, or, for that matter, how this coupling is affected by the geometry or 'strength' of this link. This question arose while attempting to verify finite-size scaling for zero-dimensional crossover 12 . We had measured the heat capacity of helium in arrays of (1 µm) 3 and (2 µm) 3 boxes linked by channels of 1 µm × 1 µm × 0.019 µm and 2 µm × 2 µm × 0.010 µm respectively. These data did not scale anywhere in the critical region 13 . The lack of scaling is unexpected, because for both twoand one-dimensional crossover, at least for T > T λ , other data do scale 14 . More significantly, an analysis of the zero-dimensional data suggested that the smaller boxes had a higher heat capacity than expected 13 . This might result from ...

show abstract

“…In addition, the specific heat is sensitive to the universal value of in a different way from that of the mixtures in the thermodynamic limit. We note that we have reported results for the superfluid density of confined mixtures at a single value of L which were also shown to scale on the same locus as for x 0 [12]. However, the specific heat provides a much more sensitive way to test universality because is very close to zero.…”

mentioning

confidence: 69%

Universality and Finite-Size Scaling of the Specific Heat ofHe3−He4Mixtures

Kimball

Gasparini²

2005

Phys. Rev. Lett.

Self Cite

View full text Add to dashboard Cite

We have measured the heat capacity of (3)He-(4)He mixtures confined in films of thickness 48.3 and 986.9 nm. The confinement is defined by direct bonding of two silicon wafers. The heat capacity is measured using an ac technique and then transformed to correct for exponent renormalization effects. The data address the expected universal critical behavior along the lambda line as function of (3)He concentration. We discuss the results of several analyses of the data, and we show that a universal collapse can be achieved for all the mixtures. However, this is on a locus which differs from that of the pure system. An alternative analysis is also presented which yields collapse of all the data under certain assumptions. We believe these data are the first to test universality of finite-size scaling for the specific heat along a locus of transitions.

show abstract

Superfluid Fraction ofH3e−H4

Cited by 17 publications

References 30 publications

The Kosterlitz–Thouless transition in thin films: a Monte Carlo study of three-dimensional lattice models

The Kosterlitz–Thouless transition in thin films: a Monte Carlo study of three-dimensional lattice models

Coupling and proximity effects in the superfluid transition in 4He dots

Universality and Finite-Size Scaling of the Specific Heat ofHe3−He4Mixtures

Contact Info

Product

Resources

About