Wolff algorithm: Difference between revisions

Revision as of 12:41, 14 May 2013

Revision as of 21:58, 20 August 2013

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{{Merge|Monte Carlo method| discuss=Talk:Monte Carlo method|date=June 2012}}

The '''Wolff algorithm''', named after [[Ulli Wolff]], is an [[algorithm]] for [[Monte Carlo simulation]] of the [[Ising model]] in which the unit to be flipped is not a single spin, as in the Isingheat modelbath or Metropolis algorithms, but a cluster of them. This cluster is defined as the set of neighbouring spins sharing the same value of the spin. The Wolff algorithm is an improvement over the [[Swendsen–Wang algorithm]] because it tendshas toa larger probability of formflipping bigger clusters.

The advantage of Wolff algorithm over other algorithms for magnetic spin simulations like single spin flip is that it allows non-local moves on the energy. One important consequence of this is that in some situations (e.g. ferromagnetic Ising model or fully frustrated Ising model), the scaling of the Multicanonic simulation is <math>N^2</math>, better than <math>N^{2+z}</math>, where z is the exponent associated with the critical slowing down phenomena.