Alladi Ramakrishnan Hall

The chiral Haldane phase with SU(N) symmetry

Abhishek Roy

Institute for Theoretical Physics, Cologne

Spin chains with PSU(N) symmetry are known to have symmetry protected topological phases distinguished by boundary states and a Haldane gap. We determine the parent Hamiltonians of some of these phases at the AKLT point where the ground state is known. We demonstrate a graphical method that exploits the geometry of the ground state and allows computations for arbitrary N. Finally we make some speculative remarks on the fate of the Haldane conjecture.

(Paper: Phys. Rev. B 97, 155148, A. Roy and T. Quella)