Two-mode effective interaction in a double-well condensate

Abstract

We investigate the origin of a disagreement between the two-mode model and the exact Gross-Pitaevskii dynamics applied to double-well systems. In general this model, even in its improved version, predicts a faster dynamics and underestimates the critical population imbalance separating Josephson and self-trapping regimes. We show that the source of this mismatch in the dynamics lies in the value of the on-site interaction energy parameter. Using simplified Thomas-Fermi densities, we find that the on-site energy parameter exhibits a linear dependence on the population imbalance, which is also confirmed by Gross-Pitaevskii simulations. When introducing this dependence in the two-mode equations of motion, we obtain a reduced interaction energy parameter which depends on the dimensionality of the system. The use of this new parameter significantly heals the disagreement in the dynamics and also produces better estimates of the critical imbalance.

5 pages, 4 figures, accepted in PRA

References in corpus (5)

• Matter-wave interferometry in a double well on an atom chip
• Dynamics of a tunable superfluid junction
• Weakly linked binary mixtures of F=1 87-Rb Bose-Einstein condensates
• Global Phase Space of Coherence and Entanglement in a double-well BEC
• Tunneling phase gate for neutral atoms in a double-well lattice

Cited by in corpus (24)

• Josephson plasma oscillations and the Gross-Pitaevskii equation: Bogoliubov approach vs two-mode model
• Tunneling, self-trapping and manipulation of higher modes of a BEC in a double well
• Phase-slips and vortex dynamics in Josephson oscillations between Bose-Einstein condensates
• Dynamics in asymmetric double-well condensates
• Non-linear mixing of Bogoliubov modes in a bosonic Josephson junction
• Quantum dynamics of few dipolar bosons in a double-well potential
• Multimode model for an atomic Bose-Einstein condensate in a ring-shaped optical lattice
• Finite-temperature dynamics of a bosonic Josephson junction
• Collapse in ultracold Bose Josephson junctions
• Collective excitations and tunneling dynamics in long bosonic Josephson junctions
• Effective two-mode model in Bose-Einstein condensates versus Gross-Pitaevskii simulations
• Dynamics in multiple-well Bose-Einstein condensates
• Ground-state Bethe root densities and quantum phase transitions
• Blocked populations in ring-shaped optical lattices
• Bose-Einstein condensates in rotating ring-shaped lattices: a multimode model
• Chaos induced breakdown of Bose-Hubbard modeling
• Interaction-modulated tunneling dynamics in a mixture of Bose-Einstein condensates
• Josephson dynamics and localization revivals in ultradilute quantum liquids
• Rotation-driven transition into coexistent Josephson modes in an atomtronic dc-SQUID
• Modeled vortex dynamics on a Bose-Einstein condensate in a rotating lattice
• dc to ac Josephson transition in a dc atom superconducting quantum interference device
• dc atomtronic quantum interference device: quantum superposition of persistent-current states and a parity-protected qubit
• Square wave oscillation of soliton in double-well potential trapped BEC
• Vortex dynamics in rotating dipolar supersolids across Josephson and self-trapping regimes