• DOI:10.1088/1367-2630/abb911
• Corpus ID: 221703358

Stable two-dimensional soliton complexes in Bose–Einstein condensates with helicoidal spin–orbit coupling

@article{Kartashov2020StableTS,
  title={Stable two-dimensional soliton complexes in Bose–Einstein condensates with helicoidal spin–orbit coupling},
  author={Yaroslav V. Kartashov and E. Ya. Sherman and Boris A. Malomed and Vladimir V. Konotop},
  journal={New Journal of Physics},
  year={2020},
  volume={22}
}

• Y. Kartashov, E. Sherman, +1 author V. Konotop
• Published 15 September 2020
• Physics
• New Journal of Physics

We show that attractive two-dimensional (2D) spinor Bose–Einstein condensates with helicoidal spatially periodic spin–orbit coupling (SOC) support a rich variety of stable fundamental solitons and bound soliton complexes. Such states exist with chemical potentials belonging to the semi-infinite gap in the band spectrum created by the periodically modulated SOC. All these states exist above a certain threshold value of the norm. The chemical potential of fundamental solitons attains the bottom of the lowest band, whose locus is a ring in the space of Bloch momenta, and the radius of the non-monotonous function of the SOC strength. The chemical potential of soliton complexes does not attain the band edge. The complexes are bound states of several out-of-phase fundamental solitons whose centers are placed at local maxima of the SOC-modulation phase. In this sense, the impact of the helicoidal SOC landscape on the solitons is similar to that of a periodic 2D potential. In particular, it can compensate repulsive forces between out-of-phase solitons, making their bound states stable. Extended stability domains are found for complexes built of two and four solitons (dipoles and quadrupoles, respectively). They are typically stable below a critical value of the chemical potential.