Publications (2)0 Total impact
-
[show abstract]
[hide abstract]
ABSTRACT: We study the influence of the quadratic Zeeman effect in the Mott-insulator phases of hard-core spin-3/2 fermions. We show that contrary to spinor bosons, any quadratic Zeeman coupling preserves a $SU(2)\otimes SU(2)$ symmetry, leading for large-enough quadratic Zeeman coupling to an isotropic pseudo-spin-1/2 Heisenberg antiferromagnet. Depending on the scattering lengths, on 1D lattices the quadratic Zeeman coupling can induce either a Kosterlitz-Thouless transition between a gapped dimerized spin-3/2 phase and a gapless pseudo-spin-1/2 antiferromagnet, or a commensurate-incommensurate transition from a gapless spin-liquid into the pseudo-spin-1/2 antiferromagnet. Similar arguments allow to foresee corresponding transitions on ladder type and square lattices. We analyze various observables which should reveal in experiments these phases. Comment: 4 pages, 3 figures
02/2010;
-
[show abstract]
[hide abstract]
ABSTRACT: We analyze by means of Matrix-Product-State simulations the correlation dynamics of strongly-correlated superfluid Bose gases in one-dimensional time-dependent optical lattices. We show that, as for the case of abrupt quenches, a quasi-adiabatic modulation of the lattice is characterized by a relatively long transient regime for which quasi-local single-particle correlation functions have already converged to a new equilibrium, whereas long-range correlations and particularly the quasi-condensate fraction may still present a very significant dynamics well after the end of the lattice modification. We also address the issue of adiabaticity by considering the fidelity between the time-evolved state and the ground-state of the final lattice. Comment: 4 pages, 4 figures
05/2009;
