0000000000430197

AUTHOR

Joachim Wuttke

0000-0002-4028-1447

showing 3 related works from this author

Universality classes for wetting in two-dimensional random-bond systems

1991

Interface-unbinding transitions, such as those arising in wetting phenomena, are studied in two-dimensional systems with quenched random impurities and general interactions. Three distinct universality classes or scaling regimes are investigated using scaling arguments and extensive transfer-matrix calculations. Both the critical exponents and the critical amplitudes are determined for the weak- and the strong-fluctuation regime. In the borderline case of the intermediate-fluctuation regime, the asymptotic regime is not accessible to numerical simulations. We also find strong evidence for a nontrivial delocalization transition of an interface that is pinned to a line of defects.

Physicssymbols.namesakeDelocalized electronCondensed matter physicssymbolsWettingHamiltonian (quantum mechanics)Critical exponentTransfer matrixScalingSchrödinger equationUniversality (dynamical systems)Physical Review B
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Mode-coupling crossover in viscous toluene revealed by neutron and light scattering

1998

The dynamics of supercooled toluene, studied in a GHz-THz range by incoherent neutron and depolarized light scattering, is found to be in full accord with mode coupling predictions. Around the susceptibility minimum, neutron spectra are wavenumber independent and proportional to light scattering data; the fast β-relaxation scaling law applies; amplitude and frequency diverge with power laws that extrapolate towards a crossover temperature Tc K.

Physicsbusiness.industryScatteringCondensed Matter PhysicsMolecular physicsPower lawSmall-angle neutron scatteringLight scatteringElectronic Optical and Magnetic MaterialsOpticsMode couplingQuasielastic neutron scatteringWavenumberNeutronbusiness
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Relaxation and phonons in viscous and glassy orthoterphenyl by neutron scattering

1993

We present an extended set of incoherent neutron scattering measurements on the van der Waals liquido-terphenyl, obtained by time-of-flight and backscattering spectroscopy. In the supercooled liquid regime, data from three instruments are combined and analysed in terms of the selfcorrelationS(Q, t). In the time range 1...100 ps, the crossover from α-to β-relaxation is well described by the masterfunction of mode coupling theory, and fitted parameters are consistent with the previously established critical temperatureT c [Z. Phys. B83, 175 (1991)]. In the glassy regime, vibrations are harmonic and can be described by a density of states. Deviations at lowQ are quantitatively explained by a m…

PhysicsCondensed matter physicsPhononScatteringIncoherent scatterNeutron scatteringCondensed Matter PhysicsElectronic Optical and Magnetic Materialssymbols.namesakeMode couplingDensity of statessymbolsRelaxation (physics)General Materials Sciencevan der Waals forceZeitschrift f�r Physik B Condensed Matter
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