The concept of turbulence is one of physics’ most persistent challenges, defying a simple description despite decades of research. Adding quantum mechanics into the mix only makes things more complicated.

BECs are formed when atoms are cooled down to close to absolute zero. In this state they behave as a single coherent quantum fluid. They enable the observation of quantum behaviour on a macroscopic scale, enabling breakthroughs in fundamental physics and ultra‑precise technologies.

Waves can form within a BEC when it’s disturbed, just like in any other fluid. These can travel through the material, interacting, cascading and ultimately forming turbulent patterns.

When the turbulence is weak, and the chaotic interactions are small, perturbative wave‑interaction theories work well. A complete, simple theory of strong turbulence, however, remains elusive. Nonlinearities dominate and approximations break down.

The new paper sets out the conditions for a BEC to shift from weak to strong turbulence, offering a clearer way to interpret experiments and simulations. The work explains how nonlinear interactions, external driving, and dissipation help to shape the turbulent cascade. This process is analogous to classical turbulence but is fundamentally altered by quantum mechanics.

The authors emphasise that distinguishing the two turbulent regimes is essential for interpreting modern ultracold-atom experiments, where turbulence can be intentionally engineered using a shaking potential trap.

As BECs continue to serve as pristine platforms for simulating complex fluid behaviour, understanding their turbulent states is becoming increasingly important. The results of this paper will be invaluable for future investigations into quantum turbulence, non-equilibrium statistical physics, and the boundary where order gives way to chaos in quantum matter.