Emission of particles from a parametrically driven condensate in a one-dimensional lattice

Abstract

We investigate particle emission, driven by periodically modulating the interaction strength, from three coupled Bose-Einstein condensates in a one-dimensional lattice. Within perturbative analyses, which lead to the regimes of instabilities for different modes, we not only obtain two main frequencies, under which the system can emit a large particle jet, but also find that the emission is distinctly intermittent rather than continuous. The time evolution of the trapped particles exhibits a stairlike decay, and a larger drive induces a more significant intermittency. We further shed light on the dynamics of the stimulating process, and demonstrate that instead of a real suspension, the intermittency represents a build-up stage of the particles. The theoretical framework might be generalized, to the explorations on other multiple-condensate systems with analogous configurations and couplings.

Effects of drive imbalance on the particle emission from a Bose–Einstein condensate in a one-dimensional lattice

“…[27,28] We introduce, in the context of mean-field approach, the expectation values of a j≥0 = â j≥0 and b j≥0 = b j≥0 , where their squares represent the number of particles on site j. In the fireworks experiments, [17,[19][20][21][22] the average dc scattering lengths were generally kept small, and in a previous work we have demonstrated that a finite U did not qualitatively change the results, [27] thus we take the limit of U = 0 for simplicity. We begin from the equilibrium at g = 0, which leads to the Heisenberg equations of motion for a j≥0 (taking units where h = 1)…”

“…where G j1 (t) = i j−2 jJ j (2J l t)θ (t)/J l t is the time-domain Green's function with J n (z) being the Bessel function of the first kind. [27] To describe the nonlinear dynamics of the system, one can directly solve Eq. (2) through Eq.…”

“…Subsequently, a number of experimental and theoretical groups have performed a series of follow-up investigations and revealed various new aspects, [19][20][21][22][23][24][25][26] e.g., the jet substructure in nonuniform and rotating condensates [20] and correlated jets from a driven matter-wave soliton. [22] In particular, semi-infinite and infinite lattice models were introduced to mimic the behaviors of the trapped particles in a transparent way, [27,28] where the time evolution of the atoms in the horizontal plane was simulated by the hopping of particles from the condensate to the "leads" and between neighboring sites, and the spatial expansion was simply limited in one dimension.…”

Resonant enhancement of particle emission from a parametrically driven condensate in a one-dimensional lattice

“…We can numerically solve these equations, using the techniques discussed in Ref. [18]. Equivalently, we can truncate the leads and directly solve Eqs.…”

“…In a previous work we analyzed a minimal model of these experiments, which demonstrated how the modulated interactions lead to particle emission [18]. The model consists of a semi-infinite 1D lattice where a deep local potential confines a condensate to the boundary site.…”