Headway Made in “Getting” Quantum Turbulence

Researchers have now demonstrated how energy disappears in quantum turbulence, and that is critical when understanding turbulence in microscopic to planetary scales. Researchers at Lancaster University conducted a new study of quantum wave turbulence together with researchers at Aalto University. The findings, published in Nature Physics, demonstrate a new understanding of how wave-like motion transfers energy from macroscopic to microscopic length scales. Results confirm a theoretical prediction about how the energy is dissipated at small scales.

Quantum turbulence at large scales is challenging to simulate. On a small scale, quantum turbulence differs from classical turbulence because the turbulent flow of a quantum fluid is confined around line-like flow centers called vortices and can only take certain quantized values. Granularity makes quantum turbulence easier to capture in a theory, and mastering quantum turbulence will help physicists understand classical turbulence as well.

A greater understanding is important to improve the aerodynamics of vehicles, predict the weather with better accuracy, or control water flow in pipes.

The formation of quantum turbulence around a single vortex remained elusive for decades despite an entire field of physicists working on quantum turbulence trying to find it. This includes people working on superfluids and quantum gases. The theorized mechanism behind this process is known as the Kelvin wave cascade.

The team of researchers studied turbulence in the Helium-3 isotope in a unique, rotating ultra-low temperature refrigerator in the Low Temperature Laboratory at Aalto. They found that microscopic scales called Kelvin waves act on individual vortices by continually pushing energy to smaller and smaller scales – leading to the scale at which energy dissipation occurs.

The team’s next project will manipulate a single quantized vortex using nano-scale devices submerged in superfluids.