A generalized duality argument, similar to the treatment of the two-dimensional Ising model by Kramers and Wannier, is used to locate the transition temperature of the eightvertex model in three dimensions.
Given a simple self-dual quantum Hamiltonian $H=KB+\ensuremath{\Gamma}\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{B}$, where K and $\ensuremath{\Gamma}$ are coupling constants, and the condition that $[B,[B,[B,\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{B}]]]=16[B,\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{B}]$, then we construct an infinite set of conserved charges Q2n; [H,Q2n]=0. In simple models, like the two-dimensional Ising or Baxter eight-vertex, these charges appear in the associated quantum theories and are equivalent to those which result from the transfer-matrix formulation and exact quantum integrability of the system. The power of our result is that it is an operator statement and does not refer to the number of dimensions or the nature of the space-time manifold: lattice, continuum, or loop space. It is suggested how the establishment of this link between duality and integrability could be used to exploit the Kramers-Wannier-type self-duality of the four-dimensional SU(N) gauge theory to find hidden symmetry.
The 2D quantum phase transition that occurs in a square lattice of Josephson-coupled p +/- ip superconductors is an example of how four-body interactions in d = 2 reproduce nonperturbative effects caused by two-body interactions in d = 1. The ordered phase has an unconventional "bond order" of the local T-breaking variable. This problem can be analyzed using an exact self-duality; this duality in classical notation is the 3D generalization of the Kramers-Wannier duality of the 2D Ising model, and there are similar exact dualities in dimensions d > or = 3. We discuss the excitation spectrum and experimental signatures of the ordered and disordered phases, and the relationship between our model and previously studied behavior of 2D boson models with four-boson interactions.
We show that for an even-dimensional hypercubic lattice one can modify the construction of a dual lattice to have the correspondence edge-edge instead of the conventional correspondence edge-(d−1)-dimensional face. This gives a straightforward generalization of Kramers-Wannier duality for an even-dimensional Ising model. In the same way as the partition function for the 2D Ising model is related to a sum over paths on a torus, higher-dimensional models involve sums over paths on Riemannian surfaces of higher genus. The critical temperature can be located only in the d=2 case in which all topological effects disappear from the thermodynamic limit. The duality in higher dimensions, however, being weak, leads nevertheless to some interesting relations for sums over paths on Riemannian surfaces, which can be considered as a topological characteristic of a critical point.