arXiv subjects

Yangui Zhou

Publications and source records attributed to Yangui Zhou.

3 recordsLinked to original sources

arXiv2023

Vortex solitons in quasi-phase-matched photonic crystals

We report solutions for stable compound solitons in a three-dimensional quasi-phase-matched photonic crystal with the quadratic ($χ^{(2)}$) nonlinearity. The photonic crystal is introduced with a checkerboard structure, which can be realized by means of the available technology. The solitons are built as four-peak vortex modes of two types, rhombuses and squares (intersite- and onsite-centered self-trapped states, respectively). Their stability areas are identified in the system's parametric space (rhombuses occupy an essentially broader stability domain), while all bright vortex solitons are subject to strong azimuthal instability in uniform $χ^{(2)}$ media. Possibilities for experimental realization of the solitons are outlined.

physics.optics↗

arXiv2022

Vortex gap solitons in spin-orbit-coupled Bose-Einstein condensates with competing nonlinearities

The formation and dynamics of full vortex gap solitons (FVGSs) is investigated in two-component Bose-Einstein condensates with spin-orbit coupling (SOC), Zeeman splitting (ZS), and competing cubic and quintic nonlinear terms, while the usual kinetic energy is neglected, assuming that it is much smaller than the SOC and ZS terms. Unlike previous SOC system with the cubic-only attractive nonlinearity, in which solely semi-vortices may be stable, with the vorticity carried by a single component, the present system supports stable FVGS states, with the vorticity present in both components (such states are called here full vortex solitons, to stress the difference from the half-vortices). They populate the bandgap in the system's linear spectrum. In the case of the cubic self-attraction and quintic repulsion, stable FVGSs with a positive effective mass exist near the top of the bandgap. On the contrary, the system with cubic self-repulsion and quintic attraction produces stable FVGSs with a negative mass near the bottom of the bandgap. Mobility and collisions of FVGSs with different topological charges are investigated too.

cond-mat.quant-gas↗

arXiv2021

Geometric phase with full-wedge and half-wedge rotation in nonlinear frequency conversion

When the quasi-phase matching (QPM) parameters of the $χ^{(2)}$ nonlinear crystal rotate along a closed path, geometric phase will be generated in the signal and idler waves that participate in the nonlinear frequency conversion. In this paper, we study two rotation schemes, full-wedge rotation, and half-wedge rotation, of the QPM parameters in the process of fully nonlinear three-wave mixing. These two schemes can effectively suppress the uncertainty in creating the geometric phase in the nonlinear frequency conversion process when the intensity of the pump is depleted. The finding of this paper provides an avenue toward constant control of the geometric phase in nonlinear optics applications and quantum information processing.

physics.optics↗