Collisional dynamics of symmetric two-dimensional quantum droplets

Abstract

The collisional dynamics of two symmetric droplets with equal intraspecies scattering lengths and particle number density for each component is studied by solving the corresponding extended Gross−Pitaevskii equation in two dimensions by including a logarithmic correction term in the usual contact interaction. We find the merging droplet after collision experiences a quadrupole oscillation in its shape and the oscillation period is found to be independent of the incidental momentum for small droplets. With increasing collision momentum the colliding droplets may separate into two, or even more, and finally into small pieces of droplets. For these dynamical phases we manage to present boundaries determined by the remnant particle number in the central area and the damped oscillation of the quadrupole mode. A stability peak for the existence of droplets emerges at the critical particle numberN_c ≃ 48 for the quasi-Gaussian and flat-top shapes of the droplets.

Graphical abstract

Keywords

ultracold atoms / quantum droplets / collisions

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Acknowledgements

The authors are grateful to Dr. Li Chen for illuminating discussions on FFT. This work was supported by the National Natural Science Foundation of China (Grant No. 12074340) and the Science Foundation of Zhejiang Sci-Tech University (ZSTU) under Grant Nos. 20062098-Y and 21062339-Y.

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