Soliton trains after interaction quenches in Bose mixtures

Year: 2021

Authors: Cidrim A., Salasnich L., Macri T.

Autors Affiliation: Univ Fed Sao Carlos, Dept Fis, BR-13565905 Sao Carlos, Brazil; Univ Padua, Dipartimento Fis & Astron Galileo Galilei, Via Marzolo 8, I-35131 Padua, Italy; INFN, Sez Padova, Via Marzolo 8, I-35131 Padua, Italy; CNR INO, Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy; Univ Padua, Padua Quantum Technol Res Ctr, Via Gradenigo 6-b, I-35131 Padua, Italy; Univ Fed Rio Grande do Norte, Dept Fis Teor & Expt, Natal, RN, Brazil; Int Inst Phys, Natal, RN, Brazil

Abstract: We investigate the quench dynamics of a two-component Bose mixture and study the onset of modulational instability, which leads the system far from equilibrium. Analogous to the single-component counterpart, this phenomenon results in the creation of trains of bright solitons. We provide an analytical estimate of the number of solitons at long times after the quench for each of the two components based on the most unstable mode of the Bogoliubov spectrum, which agrees well with our simulations for quenches to the weak attractive regime when the two components possess equal intraspecies interactions and loss rates. We also explain the significantly different soliton dynamics in a realistic experimental homonuclear potassium mixture in terms of different intraspecies interaction and loss rates. We investigate the quench dynamics of the particle number of each component estimating the characteristic time for the appearance of modulational instability for a variety of interaction strengths and loss rates. Finally we evaluate the influence of the beyond-mean-field contribution, which is crucial for the ground-state properties of the mixture, in the quench dynamics for both the evolution of the particle number and the radial width of the mixture. In particular, even for quenches to strongly attractive effective interactions we do not observe the dynamical formation of solitonic droplets.


Volume: 23 (2)      Pages from: 023022-1  to: 023022-10

More Information: We thank D Luo, R Hulet, and S Wuster for useful discussions. This research was developed with the help of XMDS2 software [41]. We thank the High Performance Computing Center (NPAD) at UFRN for providing computational resources. TM acknowledges CNPq for support through Bolsa de produtividade em Pesquisa n.311079/2015-6. This work was supported by the Serrapilheira Institute (Grant No. Serra-1812-27802), CAPES-NUFFIC Project No. 88887.156521/2017-00. TM thanks the Physics Department of the University of L´Aquila for the hospitality where part of the work was done. AC is supported by FAPESP through Grant No. 2017/09390-7. LS acknowledges the BIRD project `Superfluid properties of Fermi gases in optical potentials´ of the University of Padova for financial support.
KeyWords: solitons, modulational instability, quench dynamics, multi-component BECs
DOI: 10.1088/1367-2630/abdbe2