arXiv:1401.6401 · Physical Review B
Topological order-by-disorder in orbitally degenerate dipolar bosons on a zigzag lattice
Gaoyong Sun, T. Vekua
Abstract
Spinor bosons offer a conceptually simple picture of macroscopic quantum behavior of topological order-by-disorder: The paramagnetic state of two-component dipolar bosons in an orbitally degenerate zigzag lattice is unstable against infinitesimal quantum fluctuations of orbitals, $\ensuremath{\lambda}$, towards developing nonlocal hidden order. Adjacent to the topological state a locally correlated exact ground state with spontaneously a quadrupoled lattice constant is realized for the broad parameter regime. The topological order is extremely robust surviving the $\ensuremath{\lambda}\ensuremath{\rightarrow}\ensuremath{\infty}$ limit where the ground state evolves into the Majumdar-Ghosh state of a frustrated spin-$\frac{1}{2}$ chain.