Supersolid-like solitons in two-dimensional nonmagnetic spin-orbit coupled spin-1 and spin-2 condensates

TL;DR

This paper demonstrates the spontaneous formation of supersolid-like super-lattice and stripe solitons in two-dimensional Rashba spin-orbit coupled spin-1 and spin-2 Bose-Einstein condensates, revealing new stable and excited states with complex structures.

Contribution

It introduces the existence of supersolid-like solitons in nonmagnetic spinor BECs with spin-orbit coupling, including their structures, stability, and dependence on coupling strength, which is a novel finding.

Findings

Circularly symmetric solitons with vorticity in weak SO-coupled spin-1 BECs.

Multiring structured solitons at stronger SO-coupling.

Emergence of stripe and super-lattice solitons as excited states at higher SO-coupling.

Abstract

We demonstrate spontaneous generation of spatially-periodic supersolid-like super-lattice and stripe solitons in Rashba spin-orbit (SO) coupled spin-1 and spin-2 quasi-two-dimensional nonmagnetic Bose-Einstein condensates (BECs). The solitons in a weakly SO-coupled spin-1 BEC are circularly-symmetric of $(-1, 0, +1)$ and $(0, +1, +2)$ types and have inherent vorticity; the numbers in the parentheses are the winding numbers in hyper-spin components $+1, 0, -1$, respectively. The circularly-symmetric solitons in an SO-coupled spin-2 BEC are of types $(-2, -1, 0, +1, +2)$ and $(-1, 0, +1, +2, +3)$ with the former being the ground state, where the winding numbers correspond to spin components $+2, +1, 0, -1, -2$, respectively. For stronger SO-coupling strengths, these solitons acquire a multiring structure while preserving the winding numbers. Quasi-degenerate stripe and super-lattice solitons, besides a circularly-asymmetric soliton, also emerge as excited stationary states for stronger SO-coupling strengths in spin-1 and spin-2 BECs. pla-cl.tex