#### 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)

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