Dynamics of quantum-correlated one-dimensional Bose gases

Abstract

Bosonic Josephson junctions (BJJs) have been realised across various platforms and their dynamics have been extensively studied since their first discovery in the 1990s. While prior studies have predominantly delved into the mean-field dynamics of BJJ, we focus on the dynamics of quantum-correlated states in the BJJ with an emphasis on fluctuations. Our specific BJJ involves a pair of onedimensional (1D) Bose gases trapped in a double well on an atom chip. In order to prepare the many-body system in the strongly quantum-correlated regime, we employ a splitting procedure that protects dynamics in the relative degree of freedom from the thermal noises which otherwise dominate over the quantum noises at finite temperatures. Furthermore, we show how to optimise the quantum correlations in the multimode BJJ and demonstrate how the improved correlations prolong the phase coherence in the spatially extended 1D system. Our work provides new ways for engineering correlations and entanglement in the external degree of freedom of interacting many-body systems.