Dynamical phase diagram of a one-dimensional Bose gas in a box with a tunable weak link: From Bose-Josephson oscillations to shock waves

Abstract

We study the dynamics of one-dimensional bosons trapped in a box potential, in the presence of a barrier creating a tunable weak-link, thus realizing a one dimensional Bose-Josephson junction. By varying the initial population imbalance and the barrier height we evidence different dynamical regimes. In particular we show that at large barriers a two mode model captures accurately the dynamics, while for low barriers the dynamics involves dispersive shock waves and solitons. We study a quench protocol that can be readily implemented in experiments and show that self-trapping resonances can occur. This phenomenon can be understood qualitatively within the two-mode model.

Quantum fluctuations in atomic Josephson junctions: the role of dimensionality

“…Analyzing the full dynamics at the Gross-Pitaevskii level, one obtains rich phase diagram including dissipative, self-trapped regimes [11]. Analysis with D = 1 [12,13] and D = 2 [14,15] have highlighted the emergence of novel dissipation mechanisms, dispersive shock waves and BKT transition. Moreover, the tunability of the interaction strength via Feshbach resonances allowed investigations with fermionic superfluids near the BEC-BCS crossover, in experimental [16][17][18][19] and theoretical [20][21][22][23] studies.…”

Dissipation in a Finite Temperature Atomic Josephson Junction

“…Viewed differently, the Josephson junction separating two parts of a superfluid can also be viewed as a barrier acting against the underlying superflow: as such, superflow dissipation can emerge even strictly at T = 0, by the generation of sound waves, and even nonlinear excitations, such as solitons [36,37], vortices [17,18,[38][39][40][41][42] and shock waves [37,43], depending on system geometry and dimensionality. Such dynamical excitation features across a Josephson junction, well-known as phase slips in the context of superconductors [44,45], superfluids [4,7] ultracold transport [28,33,36,38,40,41,46,47], have also been observed in recent ultracold experiments with fermionic superfluids [17,18].…”