Séminaire du LPTMS: Christian Hagendorf

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15/01/2013    
11:00 - 12:00

LPTMS, salle 201, 2ème étage, Bât 100, Campus d'Orsay
15 Rue Georges Clemenceau, Orsay, 91405
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Spin chains with dynamical lattice supersymmetry

Christian Hagendorf, Université de Genève

Starting from simple observations about the spectrum of the spin-1/2 XXZ and XYZ Heisenberg chains at particular anisotropy I will show how to construct a representation of the N=(2,2) supersymmetry algebra on the lattice. The supercharges are dynamical: they change the number of sites. The construction generalises to higher spin. In particular, it allows to identify lattice precursors of the N=(2,2) superconformal minimal models. The supersymmetry allows to prove the existence of zero-energy ground states which have often rich properties related to enumerative combinatorics. I will discuss in detail the case of the Fateev-Zamolodchikov chain at spin one whose ground-state components are related to the weighted enumeration of alternating sign matrices.

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