Chiral Haldane phases of SU(N) quantum spin chains

Abhishek Roy, Thomas Quella
2018 Physical review B  
Gapped quantum spin chains with symmetry PSU(N)=SU(N)/Z(N) are known to possess N distinct symmetry protected topological phases. Besides the trivial phase, there are N-1 Haldane phases which are distinguished by the occurrence of massless boundary spins. Motivated by the potential realization in alkaline-earth atomic Fermi gases, we explicitly construct previously unknown Hamiltonians for two classes of chiral AKLT states and we discuss their physical properties. We also point out a deep
more » ... tion between symmetry protection in gapped and gapless 1D quantum spin systems and its implications for a potential multicritical nature of topological phase transitions.
doi:10.1103/physrevb.97.155148 fatcat:tm4byyyv3vdmxoii5hwsfcs5vm