Spin chains with dynamical lattice supersymmetry
U. de Genève
Mon, Feb. 04th 2013, 11:00
Salle Claude Itzykson, Bât. 774, Orme des Merisiers
Motivated by simple observations about the spectrum of the spin-1/2 XXZ and XYZ Heisenberg models with particular anisotropy, I will show how to construct an exact supersymmetry algebra relevant to spin chains on the lattice. The supercharges are dynamical: they change the number of sites. The construction generalises to higher spin, and leads to lattice versions of the N = 2 superconformal minimal models. The supersymmetry allows to prove the existence of zero-energy ground states which have often rich and surprising 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.