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Résumé |
Quantum magnets in 2 spatial dimensions are effectively described by a 2+1D abelian-higgs theory with monopoles. Such materials support a phase of highly entangled ground state called the Valence Bond Solid phase, where spin-1/2 excitations are confined into spin-1 object. Moreover the ground state breaks lattice symmetries spontaneously and is therefore degenerate. The effective description has a striking resemblance to a version of QCD with adjoint matter, including the N=1 and N=2 Super Yang-Mills theory as well as theta=pi pure Yang-Mills theory. The common feature of all these theories is that they are confining and support domain walls which, in turn, are deconfining. The underlying reason for deconfinement are the underlying 't Hooft anomalies between various global symmetries of the theories. |
