Quantum vortex visualization in superfluid helium

Superfluid helium is an important model system to study quantum hydrodynamics. Numerous researches have been reported on fascinating phenomena including superfluidity, unusually low viscosity, and the emergence of the quantum vortex. Here, we demonstrated the visualization of the quantum vortices, which are intrinsically unable to be seen. We prepared many nanoparticles in superfluid helium by using the laser ablation technique. The fabricated nanoparticles are trapped at the core of the quantum vortices. By imaging the scattered light from the nanoparticles, we visualized the motion of the quantum vortices.