2011/08/31 by Hoi-Yin Hui, Ryan Barnett, Rajdeep Sensarma +1
Physics and Astronomy · #Bose–Hubbard model #Boson #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Hubbard model #Instability #Lattice (music) #Mott insulator #Mott transition #Optical lattice #Phase (matter) #Phase diagram #Physics #Quantum #Quantum many-body systems #Quantum mechanics #Quantum, superfluid, helium dynamics #Superconductivity #Superfluidity #Ultracold atom #cond-mat.quant-gas
paper · pdf · doi:10.1103/physreva.84.043615
published as Phys. Rev. A 84, 043615 (2011) · 11 pages, 6 figures
openalex publication_date 2011/10/11 · arxiv created 2011/10/18 · arxiv updated 2015/03/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We analyze the dynamical and energetic instabilities of spin currents in a system of two-component bosons in an optical lattice, with a particular focus on the N'eel state. We consider both the weakly interacting superfluid and the strongly interacting Mott insulating limits as well as the regime near the superfluid-insulator transition and establish the criteria for the onset of these instabilities. We use Bogoliubov theory to treat the weakly interacting superfluid regime. Near the Mott transition, we calculate the stability phase diagram within a variational Gutzwiller wave-function approach. In the deep Mott limit we discuss the emergence of the Heisenberg model and calculate the stability diagram within this model. Though the Bogoliubov theory and the Heisenberg model (appropriate for the deep superfluid and the deep Mott-insulating phase, respectively) predict no dynamical instabilities, we find, interestingly, that between these two limiting cases there is a regime of dynamical instability. This result is relevant for the ongoing experimental efforts to realize a stable N'eel-ordered state in multicomponent ultracold bosons.