Dynamics of Bose-Einstein condensates in a one-dimensional optical lattice with double-well potential

Abstract

We study dynamical behaviors of the weakly interacting Bose-Einstein condensate in the onedimensional optical lattice with an overall double-well potential by solving the time-dependent Gross-Pitaevskii equation. It is observed that the double-well potential dominates the dynamics of such a system even if the lattice depth is several times larger than the height of the double-well potential. This result suggests that the condensate flows without resistance in the periodic lattice just like the case of a single particle moving in periodic potentials. Nevertheless, the effective mass of atoms is increased, which can be experimentally verified since it is connected to the Josephson oscillation frequency. Moreover, the periodic lattice enhances the nonlinearity of the double-well condensate, making the condensate more "self-trapped" in the π-mode self-trapping regime.

Phase coherence and fragmentation of two-component Bose-Einstein condensates loaded in state-dependent optical lattices

“…Instead, some studies have developed novel analytic methods [34][35][36][37]. On the other hand, for BECs in shallow optical lattices, theoretical analysis of phase decoherence in 1D has been extensively performed via an extended Gross-Pitaevskii equation (GPE) approach [38], or via the Truncated Wigner Approximation (TWA) approach [31].…”

“…In many cases, theoretical studies in deep lattices have used the Bose-Hubbard model (BHM) [18-20, 23, 24, 32] or Time-Evolving Bloch Decimation (TEBD) approach [33], both of which become problematic when there are many atoms per well, as in the one-component experiments of [7]. Instead, some studies have developed novel analytic methods [34][35][36][37]. On the other hand, for BECs in shallow optical lattices, theoretical analysis of phase decoherence in 1D has been extensively performed via an extended Gross-Pitaevskii equation (GPE) approach [38], or via the Truncated Wigner Approximation (TWA) approach [31].…”

Quadrupolar matter-wave soliton in two-dimensional free space

“…In the past few decades, scientists have performed much theoretical and experimental research in the field of BECs after a BEC was first observed in dilute alkali gases. Rich phenomena have been revealed in the studies of BEC, such as solitons [2,3], vortex formation [4,5], Josephson oscillation [6,7], chaos [8], and symmetry breaking [9][10][11][12]. The matter-wave soliton was also experimentally observed in ultra-cold atom gases [13,14], and with the development of Feshbach resonance [15][16][17], it plays a crucial role in the research on solitons [18][19][20][21].…”