Séminaire de groupe
|Spin chains with dynamical lattice supersymmetry|
|jeudi 21 mars 2013 , 10h25|
|Salle de séminaire du groupe de Physique Statistique|
Motivated by a few simple observations about the spectrum of the 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.