1,788 research outputs found
Parallel-tempering cluster algorithm for computer simulations of critical phenomena
In finite-size scaling analyses of Monte Carlo simulations of second-order
phase transitions one often needs an extended temperature range around the
critical point. By combining the parallel tempering algorithm with cluster
updates and an adaptive routine to find the temperature window of interest, we
introduce a flexible and powerful method for systematic investigations of
critical phenomena. As a result, we gain one to two orders of magnitude in the
performance for 2D and 3D Ising models in comparison with the recently proposed
Wang-Landau recursion for cluster algorithms based on the multibondic
algorithm, which is already a great improvement over the standard
multicanonical variant.Comment: pages, 5 figures, and 2 table
Boundary field induced first-order transition in the 2D Ising model: numerical study
In a recent paper, Clusel and Fortin [J. Phys. A.: Math. Gen. 39 (2006) 995]
presented an analytical study of a first-order transition induced by an
inhomogeneous boundary magnetic field in the two-dimensional Ising model. They
identified the transition that separates the regime where the interface is
localized near the boundary from the one where it is propagating inside the
bulk. Inspired by these results, we measured the interface tension by using
multimagnetic simulations combined with parallel tempering to determine the
phase transition and the location of the interface. Our results are in very
good agreement with the theoretical predictions. Furthermore, we studied the
spin-spin correlation function for which no analytical results are available.Comment: 12 pages, 7 figures, 2 table
Information Geometry and Phase Transitions
The introduction of a metric onto the space of parameters in models in
Statistical Mechanics and beyond gives an alternative perspective on their
phase structure. In such a geometrization, the scalar curvature, R, plays a
central role. A non-interacting model has a flat geometry (R=0), while R
diverges at the critical point of an interacting one. Here, the information
geometry is studied for a number of solvable statistical-mechanical models.Comment: 6 pages with 1 figur
Fluctuation Pressure of a Stack of Membranes
We calculate the universal pressure constants of a stack of N membranes
between walls by strong-coupling theory. The results are in very good agreement
with values from Monte-Carlo simulations.Comment: Author Information under
http://www.physik.fu-berlin.de/~kleinert/institution.html Latest update of
paper also at http://www.physik.fu-berlin.de/~kleinert/31
Substrate Adhesion of a Nongrafted Flexible Polymer in a Cavity
In a contact density chain-growth study we investigate the
solubility-temperature pseudo-phase diagram of a lattice polymer in a cavity
with an attractive surface. In addition to the main phases of adsorbed and
desorbed conformations we find numerous subphases of collapsed and expanded
structures.Comment: 20 pages, 6 figure
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