Realization Of Optical Ferris Wheel Solitons In Rydberg Medium

Optical Ferris Wheels is one type of specific structured beams that is formed by the interference of two Laguerre Gaussian beams.Via a clever design of interference superposition the OFW field can realize not only the elimination of radial orbit angular momentum(OAM); but also the storage of axial OAM.This spatial distribution can be treated as a new unit for quantum information processing which also reveals a flexible control just like an optical tweezer for cold atoms.On the other hand ultracold Rydberg atoms with strong interatomic interactions,have shown many exciting properties.By utilizing Rydberg based nonlinear effects such as EIT,the absorption of the OFW field in propagation could be suppressed inducing a giant nonlinear self-focusing potential which is prospective for a long-distance propagation.This work studies the stable propagation of an OFW field in the Rydberg medium.While unlike the previous methods that used a semi-analytical variational principle to calculate soliton solutions we propose an optimization method.By using optimal parameters the diffraction kinetic energy can be perfectly compensated by the nonlocal nonlinear attractive potential realizing the OFW soliton.The major advantage of our scheme lies in the independence of intensity distribution of incident beams and the feasibility for optical beam with any waveforms.Therefore our scheme has a very strong robustness.First,we show the EIT effect has a large nonlocal nonlinear potential which can be tuned by atomic density and middle detuning.Then these two parameters are optimized with genetic algorithm ensuring a maximal fidelity for the stable propagation of the OFW field.Our results show that,for lower-order OFW fields,in a stable20mm-propagation the fidelity preserves above 0.96 with optimization for atomic density and middle detuning.However,for higher-order OFW fields,an auxiliary optimization for the probe and coupling laser amplitudes is required in order to achieve a long-distance propagation.Our achievements can be used for the experimental researches on the stable propagation of structured beams and provide a new convenient way for realizing spatial optical solitons in the future.