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Blossey, Ralf; Kinoshita, T.; Müller, Xavier; Dupont‐Roc, J.

doi:10.1023/a:1022552126239

Cited by 13 publications

(8 citation statements)

References 7 publications

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“…Above 1.95 K, there is some remaining hysteresis in the prewetting transitions, but not in the position of the KT line. Prewetting is in the two-dimensional Ising universality class, and the phase transitions in this type of system are well known to be strongly affected by disorder, [31][32][33][34] while the KT transition, which is in the XY universality class, is relatively insensitive to disorder. 35 The junction in the -T plane of the first-order prewetting line and the higher-order KT line shown in Fig.…”

Section: Discussionmentioning

confidence: 99%

Superfluid onset and prewetting of4Heon rubidium

et al. 1998

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Quartz-crystal microbalance isotherms of 4 He on rubidium are presented. The isotherms are used to locate the prewetting transition and the onset of superfluidity in the adsorbed helium films. The phase diagram of He on Rb is distinctly different from helium on either conventional strong substrates or on cesium. In particular, the superfluid transition is hysteretic and does not conform to the Kosterlitz-Thouless paradigm.

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Section: Discussionmentioning

confidence: 99%

Superfluid onset and prewetting of4Heon rubidium

et al. 1998

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“…The difference implies that the L c , at which length scale the spanning probability vanishes, scales as L c ∼ L 6 b . The L b is already exponentially large length scale for small ∆, so L c should be large enough that one can be below it in experiments, and thus a system can "apparently percolate" [36,10].…”

Section: Percolation With An External Fieldmentioning

confidence: 99%

Susceptibility and percolation in two-dimensional random field Ising magnets

Seppälä

Alava

2001

Phys. Rev. E

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The ground-state structure of the two-dimensional random field Ising magnet is studied using exact numerical calculations. First we show that the ferromagnetism, which exists for small system sizes, vanishes with a large excitation at a random field strength-dependent length scale. This breakup length scale L(b) scales exponentially with the squared random field, exp(A/delta(2)). By adding an external field H, we then study the susceptibility in the ground state. If L>L(b), domains melt continuously and the magnetization has a smooth behavior, independent of system size, and the susceptibility decays as L-2. We define a random field strength-dependent critical external field value +/-H(c)(delta) for the up and down spins to form a percolation type of spanning cluster. The percolation transition is in the standard short-range correlated percolation universality class. The mass of the spanning cluster increases with decreasing Delta and the critical external field approaches zero for vanishing random field strength, implying the critical field scaling (for Gaussian disorder) H(c) approximately (delta-delta(c))(delta), where delta(c)=1.65+/-0.05 and delta=2.05+/-0.10. Below Delta(c) the systems should percolate even when H=0. This implies that even for H=0 above L(b) the domains can be fractal at low random fields, such that the largest domain spans the system at low random field strength values and its mass has the fractal dimension of standard percolation D(f)=91/48. The structure of the spanning clusters is studied by defining red clusters, in analogy to the "red sites" of ordinary site percolation. The sizes of red clusters define an extra length scale, independent of L.

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“…In [8], the relation ρ 3 ∝ ρ 1.75±0.05 1 was obtained numerically (for a rectangular distribution of random fields), however, an exponent 2 can also be reconciled with their figure 4, when the smaller slope in the lower part of the plot is ascribed to finite-size effects. In [19], the relation…”

Section: The Modelmentioning

confidence: 99%

Depinning of a domain wall in the 2d random-field Ising model

Drossel

Dahmen

1998

Eur. Phys. J. B

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We report studies of the behaviour of a single driven domain wall in the 2-dimensional non-equilibrium zero temperature random-field Ising model, closely above the depinning threshold. It is found that even for very weak disorder, the domain wall moves through the system in percolative fashion. At depinning, the fraction of spins that are flipped by the proceeding avalanche vanishes with the same exponent beta=5/36 as the infinite percolation cluster in percolation theory. With decreasing disorder strength, however, the size of the critical region decreases. Our numerical simulation data appear to reflect a crossover behaviour to an exponent beta'=0 at zero disorder strength. The conclusions of this paper strongly rely on analytical arguments. A scaling theory in terms of the disorder strength and the magnetic field is presented that gives the values of all critical exponent except for one, the value of which is estimated from scaling arguments.Comment: 13 pages Revtex, 13 eps figure

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Untitled

Cited by 13 publications

References 7 publications

Superfluid onset and prewetting of4Heon rubidium

Superfluid onset and prewetting of4Heon rubidium

Susceptibility and percolation in two-dimensional random field Ising magnets

Depinning of a domain wall in the 2d random-field Ising model

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