arXiv subjects

Xiao-Dong Bai

Publications and source records attributed to Xiao-Dong Bai.

6 recordsLinked to original sources

arXiv2025

Rogue waves collision under incident momentum modulation in two-component Bose-Einstein condensates

The collision dynamics of two first-order rogue waves (RWs) with opposite incident momentum in two-component Bose-Einstein condensates (BECs) is studied by solving the two-component one-dimensional Gross-Pitaevskii (GP) equation. It is demonstrated that the introduction of appropriate incident momentum successfully promotes the generation of second-order RWs in the case of relatively weaker interspecies interactions compared to intraspecific interactions. The range of incident momentum that can facilitate the generation of second-order RWs under different interspecies interaction strengths is determined, and machine learning is employed to find and analyze relationships among the interspecies interaction, the incident momentum, and the offset that can lead to the generation of second-order RWs. It shows that any two parameters above exhibit a positive or negative correlation when the third parameter is fixed. These findings provide additional possibilities for generating and controlling high-order RWs.

cond-mat.quant-gas↗

arXiv2023

Magnetic supersolid phases of two-dimensional extended Bose-Hubbard model with spin-orbit coupling

The study of ultracold atomic spin systems with long-range interaction provides the possibility of searching for magnetic supersolid phases in quantum many-body scenarios. In this paper, we consider two-species Bose gases with spin-orbit coupling and nearest-neighbor interaction confined in a two-dimensional optical lattice. The competition between spin-orbit coupling and interactions creates rich ground-state diagrams with supersolid phases exhibiting phase modulations or magnetic orderings. We obtain the phase-twisted and phase-striped pair checkboard supersolid phases that are generated by the combination of spin-orbit coupling and intraspecies nearest-neighbor interaction. The introduction of interspecies nearest-neighbor interaction enriches the quantum phases of the system. It leads to the appearance of the phase-twisted and phase-striped lattice supersolid phases. In addition to the lattice supersolid phase, we find the emergence of nontrivial supersolid phases that depend on the interspecies on-site interaction strength. The lattice-insulated supersolid phase with supersolidility in one species but insulation in the other exists in the miscible domain, while the pair striped supersolid phase with stripe structures in each species is in the immiscible domain. Finally, to further characterize each phase, we discuss their spin-dependent momentum distributions and spin textures. The magnetic textures, such as antiferromagnetic, spiral and stripe orders, are shown in SS phases. The results here could help in the observe for these magnetic supersolid phases in ultracold atomic experiments with nearest-neighbor interaction and spin-orbit coupling in optical lattice.

cond-mat.quant-gas↗

arXiv2018

Polaron in a non-abelian Aubry-André-Harper model with \textit{p}-wave superfluidity

We theoretically investigate the behavior of a mobile impurity immersed in a one-dimensional quasi-periodic Fermi system with topological $p$-wave superfluidity. This polaron problem is solved by using a standard variational approach, the so-called Chevy ansatz. The polaron states are found to be strongly affected by the strength of the quasi-disorder and the amplitude of the $p$-wave pairing. We analyze the phase diagram of the polaron ground state and find four phases: two extended phases, a weakly-localized phase and a strongly-localized phase. It is remarkable that these polaron phases are directly corresponding to the four distinct phases experienced by the underlying background Fermi system. In particular, the weakly-localized polaron phase corresponds to an intriguing critical phase of the Fermi system. Therefore, the different phases of the background system can be unambiguously probed by measuring the polaron properties via radio-frequency spectroscopy. We also investigate the high-lying excited polaron states at an infinite temperature and address the possibility of studying many-body localization (MBL) of these states. We find that the introduction of $p$-wave pairing may delocalize the many-body localized states and make the system easier to thermalize. Our results could be observed in current state-of-the-art cold-atom experiments.

cond-mat.quant-gas↗

arXiv2016

Unidirectional transport of wave packets through tilted discrete breathers in nonlinear lattices with asymmetric defects

We consider the transfer of lattice wave packets through a tilted discrete breather (TDB) in opposite directions in the discrete nonlinear Schrödinger model with asymmetric defects, which may be realized as a Bose-Einstein condensate trapped in a deep optical lattice, or as optical beams in a waveguide array. A unidirectional transport mode is found, in which the incident wave packets, whose energy belongs to a certain interval between full reflection and full passage regions, pass the TDB only in one direction, while, in the absence of the TDB, the same lattice admits bi-directional propagation. The operation of this mode is accurately explained by an analytical consideration of the respective energy barriers. The results suggest that the TDB may emulate the unidirectional propagation of atomic and optical beams in various settings. In the case of the passage of the incident wave packet, the scattering TDB typically shifts by one lattice unit in the direction from which the wave packet arrives, which is an example of the tractor-beam effect, provided by the same system, in addition to the rectification of incident waves.

cond-mat.quant-gas↗

arXiv2016

Selective distillation phenomenon in two-species Bose-Einstein condensates in open boundary optical lattices

We investigate the formation of discrete breathers (DBs) and the dynamics of the mixture of two-species Bose-Einstein condensates (BECs) in open boundary optical lattices using the discrete nonlinear Schrödinger equations. The results show that the coupling of intra- and interspecies interaction can lead to the existence of pure single-species DBs and symbiotic DBs (i.e., two-species DBs). Furthermore, we find that there is a selective distillation phenomenon in the dynamics of the mixture of two-species BECs. One can selectively distil one species from the mixture of two-species BECs and can even control dominant species fraction by adjusting the intra- and interspecies interaction in optical lattices. Our selective distillation mechanism may find potential application in quantum information storage and quantum information processing based on multi-species atoms.

cond-mat.quant-gas↗

arXiv2015

Stability and phase transition of localized modes in Bose-Einstein condensates with both two- and three-body interactions

We investigate the stability and phase transition of localized modes in Bose-Einstein Condensates (BECs) in an optical lattice with the discrete nonlinear Schrödinger model by considering both two- and three-body interactions. We find that there are three types of localized modes, bright discrete breather (DB), discrete kink (DK), and multi-breather (MUB). Moreover, both two- and three-body on-site repulsive interactions can stabilize DB, while on-site attractive three-body interactions destabilize it. There is a critical value for the three-body interaction with which both DK and MUB become the most stable ones. We give analytically the energy thresholds for the destabilization of localized states and find that they are unstable (stable) when the total energy of the system is higher (lower) than the thresholds. The stability and dynamics characters of DB and MUB are general for extended lattice systems. Our result is useful for the blocking, filtering, and transfer of the norm in nonlinear lattices for BECs with both two- and three-body interactions.

cond-mat.quant-gas↗