Vortices: What’s happening inside ultracold quantum storms?
Vortices pop-up in the weather, sink drains, and even astrophysics; they are also a feature of quantum superfluids, such as an ultracold atomic gas. Quantum physics dictates that the circulation in these systems obeys certain quantization criteria. When a superfluid is disturbed vortices will form in order to satisfy this circulation constraint. Vortices look like mini-tornados, having an essentially empty core or “eye” with the surrounding atoms circulating.
Stirring up a superfluid is one way to induce vortices. Changing the interactions of the system can also do this—for instance introducing spin-orbit coupling. Vortices even nucleate as a thermal gas undergoes a phase transition into a Bose-Einstein condensate. Another cool aspect: in seeking out the lowest energy configuration, the vortices will arrange into a lattice (see image below, data taken and image created by W. Ketterle group @ MIT)
Read more to learn more about coreless vortices—a quantum storm without the ‘eye.’
Recently JQI researchers used computer simulations to predict the behavior of magnetic atoms in a dipolar Bose Einstein condensate. When the atoms were subjected to additional laser beams the magnetic interactions among the atoms caused them to sort into striking spin texture patterns, including a “coreless vortex,” a condition in which one component of the atoms circulated around another component of atoms at rest in the middle (See image in above gallery).