Many-body quantum coherence and interaction blockade in Josephson-linked Bose-Einstein condensates

Abstract

We study many-body quantum coherence and interaction blockade in two Josephson-linked Bose-Einstein condensates. We introduce universal operators for characterizing many-body coherence without limitations on the system symmetry and total particle number $N$. We reproduce the results for both coherence fluctuations and number squeezing in {\em symmetric} systems of large $N$, and reveal several peculiar phenomena that may occur in {\em asymmetric} systems and systems of small $N$. For asymmetric systems, we show that, due to an interplay between asymmetry and inter-particle interaction, the coherence fluctuations are suppressed dramatically when $|E_C/E_J|\ll 1$, and both {\it resonant tunneling} and {\it interaction blockade} take place for large values of $|E_C/E_J|$, where $E_C$ and $E_J$ are the interaction and tunneling energies, respectively. We emphasize that the resonant tunneling and interaction blockade may allow creating single-atom devices with promising technology applications. We demonstrate that for the systems at finite temperatures the formation of self-trapped states causes an anomalous behavior.

6 pages, 5 figures, accepted for publication in EPL (Europhysics Letters)

References in corpus (3)

• Matter-wave interferometry in a double well on an atom chip
• Controlled exchange interaction between pairs of neutral atoms in an optical lattice
• Phase-Dependent Spontaneous Spin Polarization and Bifurcation Delay in Coupled Two-Component Bose-Einstein Condensates

Cited by in corpus (1)

• Resonant tunneling of Bose-Einstein condensates in optical lattices