Magic Tilt Angle for Stabilizing Two-Dimensional Solitons by Dipole-Dipole Interactions
Xing-You Chen1*, You-Lin Chuang2, Chun-Yan Lin1, Chien-Ming Wu1, Yongyao Li3, Boris A. Malomed4, Ray-Kuang Lee1,2
1Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan
2Physics Division, National Center for Theoretical Sciences, Hsinchu, Taiwan
3School of Physics and Optoelectronic Engineering, Foshan University, Foshan, China
4Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
* Presenter:Xing-You Chen
In the framework of the Gross-Pitaevskii equation, we study the formation and stability of effectively twodimensional solitons in dipolar Bose-Einstein condensates (BECs), with dipole moments polarized at an arbitrary angle θ relative to the direction normal to the system’s plane. Using numerical methods and the variational approximation, we demonstrate that unstable Townes solitons, created by the contact attractive interaction, may be completely stabilized (with an anisotropic shape) by the dipole-dipole interaction (DDI), in the interval θcr<θ≤π/2. The stability boundary θcr weakly depends on the relative strength of the DDI, remaining close to the magic angle θm= arccos(1/ √3). The results suggest that DDIs provide a generic mechanism for the creation of stable BEC solitons in higher dimensions.

Keywords: soliton, dipolar BEC