Camera developed to image quantum vortices

Lancaster University researchers have developed a camera-like device that is able to image mini whirlpools in quantum liquids, believed to be a world first. Their work has been published in the journal Physical Review B.

Vortices form in stirred fluids, when water drains into a plughole, and in tornadoes and cyclones. These vortices are unpredictable — unlike in quantum liquids, where the vortices always have the same size due to quantum effects that only arise at very cold temperatures such as with the superfluid liquid helium-3. The problem is that quantum vortices by their very nature are too small to be captured without tracer particles by a conventional camera.

Physicists led by Dr Theo Noble have now developed a new type of camera which uses particle-like disturbances to take images of collections of vortices instead of light. The camera is a 5x5 array of pixels; each of the 25 pixels is a millimetre-sized cylindrical cavity with a quartz tuning fork in the middle.

The team tested the camera on vortices created by a vibrating wire in a form of ultra-cold helium. Noble explained, “The experiment works like shining a torch on a shadow puppet. We then measure the shadows cast by quantum vortices across the camera.”

Even with its low number of pixels, the new camera uncovered that most vortices form above the vibrating wire instead of developing all around it. According to Dr Viktor Tsepelin, Head of the Ultra Low Temperature Laboratory at Lancaster University, this result was not predicted by mathematical theories or numerical simulations.

Tsepelin’s goal now is to build a 90-pixel camera with a high enough resolution to image the details of development and decay of carefully prepared collections of vortices. This ability to observe the dynamics of superfluid helium-3 will improve the understanding of the turbulent motion of quantum fluids and turbulence in general.

“It is exciting to see that our prototype is working,” Tsepelin said. “The high-resolution camera could also be used to image other topological defects existing in superfluid helium-3, allowing us to have a glimpse at an analogue of the early universe.”

Image credit: ©stock.adobe.com/au/rybindmitriy

Please follow us and share on Twitter and Facebook. You can also subscribe for FREE to our weekly newsletters and bimonthly magazine.