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models:spin_models [2018/05/07 07:22]
jakobadmin [Overview]
models:spin_models [2018/05/07 07:24]
jakobadmin [Overview]
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 For $n=1$ and $Q=2$ the two types of models overlap and this special model is known as the [[models:​spin_models:​ising_model|Ising model]]. For $n=1$ and $Q=2$ the two types of models overlap and this special model is known as the [[models:​spin_models:​ising_model|Ising model]].
  
-<tabbox Why is interesting?>  ​+----
  
 <​blockquote>"​Empirically,​ one finds that all systems in nature belong to one of a comparatively small number of such universality classes. Two specific microscopic interaction Hamiltonians appear almost sufficient to encompass the universality classes necessary for static critical phenomena. ​ <​blockquote>"​Empirically,​ one finds that all systems in nature belong to one of a comparatively small number of such universality classes. Two specific microscopic interaction Hamiltonians appear almost sufficient to encompass the universality classes necessary for static critical phenomena. ​
 +
 +[...] [T]he Q-state Potts model (Potts, 1952; Wu, 1982) [and] the n-vector model (Stanley, 1968).
  
 The first of these is the Q-state Potts model (Potts, 1952; Wu, 1982). One assumes that each spin i can be in one of Q possible discrete orientations $\chi_i$ $(\chi_i =,​1,​2,​\ldots,​Q)$. If two neighboring spins i and j are in the same orientation,​ then they contribute an amount $-J$ to the total energy of a configuration. If i and j are in different orientations,​ they contribute nothing. Thus the interaction Hamiltonian is  The first of these is the Q-state Potts model (Potts, 1952; Wu, 1982). One assumes that each spin i can be in one of Q possible discrete orientations $\chi_i$ $(\chi_i =,​1,​2,​\ldots,​Q)$. If two neighboring spins i and j are in the same orientation,​ then they contribute an amount $-J$ to the total energy of a configuration. If i and j are in different orientations,​ they contribute nothing. Thus the interaction Hamiltonian is 
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 Both the Potts and n-vector hierarchies are generalization Both the Potts and n-vector hierarchies are generalization
 of the simple Ising model of a uniaxial ferromagnet. of the simple Ising model of a uniaxial ferromagnet.
 +<​cite>​[[https://​journals.aps.org/​rmp/​abstract/​10.1103/​RevModPhys.71.S358|Scaling,​ universality,​ and renormalization:​ Three pillars of modern critical phenomena]] by H.Eugene Stanley</​cite></​blockquote>​
 +<tabbox Why is interesting?> ​
 + 
 +
 +<​blockquote>"​Empirically,​ one finds that all systems in nature belong to one of a comparatively small number of such universality classes. Two specific microscopic interaction Hamiltonians appear almost sufficient to encompass the universality classes necessary for static critical phenomena. ​
 +
 +[...] [T]he Q-state Potts model (Potts, 1952; Wu, 1982) [and] the n-vector model (Stanley, 1968).
 +
 +
 <​cite>​[[https://​journals.aps.org/​rmp/​abstract/​10.1103/​RevModPhys.71.S358|Scaling,​ universality,​ and renormalization:​ Three pillars of modern critical phenomena]] by H.Eugene Stanley</​cite></​blockquote>​ <​cite>​[[https://​journals.aps.org/​rmp/​abstract/​10.1103/​RevModPhys.71.S358|Scaling,​ universality,​ and renormalization:​ Three pillars of modern critical phenomena]] by H.Eugene Stanley</​cite></​blockquote>​
  
models/spin_models.txt ยท Last modified: 2020/04/12 14:47 by jakobadmin