Two-legSU(2n)spin ladder: A low-energy effective field theory approach

P. Lecheminant, A. M. Tsvelik
2015 Physical Review B  
We present a field theory analysis of a model of two SU(2n)-invariant magnetic chains coupled by a generic interaction preserving time reversal and inversion symmetry. Contrary to the SU(2)-invariant case the zero-temperature phase diagram of such two-leg spin ladder does not contain topological phases. Only generalized Valence Bond Solid phases are stabilized when n>1 with different wave vectors and ground-state degeneracies. In particular, we find a phase which is made of a cluster of 2n
more » ... put in an SU(2n) singlet state. For n=3, this cluster phase is relevant to ytterbium ultracold atoms, with an emergent SU(6) symmetry, loaded in double well optical lattice.
doi:10.1103/physrevb.91.174407 fatcat:eltf74hidnehnf5xhd2hvkesnm