Josephson Dynamics of a Bose-Einstein Condensate Trapped in a Double-Well Potential

D. Ananikian

Hongwei Yang, Zuo Wei

The Josephson equations for a Bose–Einstein Condensate gas trapped in a double-well potential are derived with the two-mode approximation by the Gross–Pitaevskii equation. The dynamical characteristics of the equations are obtained by the numerical phase diagrams. The nonlinear self-trapping effect appeared in the phase diagrams are emphatically discussed, and the condition E c N >4 E J is presented.

Carlo Ottaviani, V. Ahufinger, R. Corbalán +1 more

Bose Einstein condensates (BECs) in double well potentials have drawn a lot of attention for the possibilities they offer to study fundamental quantum mechanical effects at the macroscopic level as well as for potential applications like interferometry, high precision measurements or thermometry. In contrast to Josephson junctions realized in superconductors and superfluids, in BEC the interatomic interactions play a crucial role leading to anharmonic Josephson oscillations, if the initial population imbalance of the two wells is below a critical value, and to macroscopic quantum self-trapping i.e, inhibition of large amplitude Josephson oscillations above the threshold for the population imbalance. In this paper, a novel technique to adiabatically control of BEC in a double-well potential is proposed. The adiabatic dynamics of a BEC in a double well potential can be described in terms of a dark variable resulting from a combination of the population imbalance and the spatial atomic coherence.

Yeong E. Kim, Alexander L. Zubarev

Amichay Vardi, J. R. Anglin

Yao-Jun Ying, Wang, Haoyu, Zhang, Ming +1 more

The Josephson effect can be observed in a Bose-Einstein condensate in a double-well potential, which is attributed to the tunneling of bosons between two wells. We propose a multi-mode theory to investigate the dynamics of local excitations in a one-dimensional condensate in a double-well potential. We show that the system can be described by two independent two-mode models. The Josephson oscillation and the self-trapping of local collective excitations are predicted analytically and confirmed by numerical simulation.