I will report on the experimental observation of solitonic vortices in an
elongated Bose-Einstein condensate. A rapid quench across the BEC
transition induces the spontaneous creation of defects (most likely
solitons) in the phase of the resulting condensate [1], following the
Kibble-Zurek mechanism. A probable evolution mechanism of such solitons
consists in their decay, due to snake instability, first to vortex rings
and finally to vortex lines mainly oriented in the radial plane of the
elongated BEC. We study the properties of these stable topological
defects, also known as solitonic vortices, by imaging them from three
orthogonal directions and through interferometric techniques [1,2]. A
stroboscopic method allows us to make a real-time imaging of the vortex
orbiting in the BEC. We detect the variation of the orbital period due to
the atom number reduction on the long term as well as effects due to the
interaction among crossing vortices.

[1] G. Lamporesi et al., Nat. Phys 9, 656 (2013)
[2] S. Donadello et al., Phys. Rev. Lett. 113, 065302 (2014)
[3] M. Tylutki et al., EPJD-ST 224, 577 (2015)