Quantum Turbulence in Superfluid Helium

Quantum turbulence in superfluid helium arises from the complex dynamics of quantised vortices within a frictionless fluid that coexists with a normal viscous component. Unlike classical turbulence, where eddies of all sizes interact continuously, quantum turbulence is underpinned by discrete vortex lines each carrying an exact quantum of circulation. At scales larger than the typical intervortex spacing, these vortices self-organise into coherent bundles and support a quasiclassical energy cascade reminiscent of the Kolmogorov spectrum. At smaller scales, however, quantisation becomes paramount and energy is transferred to Kelvin waves propagating along the vortex cores, eventually radiating phonons or rotons. Vortex reconnections and mutual friction between the superfluid and normal components govern the dissipation and decay of turbulent states. Research in this field not only deepens our understanding of non-equilibrium quantum fluids but also informs studies of neutron-star interiors, high-precision sensors and cryogenic technology.

Research from Nature Portfolio

Recent studies have visualised quantised vortex rings propagating in superfluid helium, providing decisive experimental data on the dissipative forces exerted by thermal quasiparticles. These observations resolve longstanding ambiguities in theoretical models of vortex friction and refine predictions for vortex-driven decay in a variety of quantum-fluid systems. In parallel, experiments on rotating quantum wave turbulence have demonstrated energy transfer from large-scale inertial waves down to the elusive Kelvin-wave cascade at ultralow temperatures. By modulating angular velocity, researchers have exposed a boundary-driven energy injection mechanism distinct from classical Ekman layers and have validated numerical simulations that strip away vortex reconnections to isolate the pure wave-turbulence regime.

Quantum Turbulence in Superfluid Helium publication trend

The graph below shows the total number of articles in quantum turbulence in superfluid helium across all publications each year (not limited to Nature Index journals).

Technical terms

Quantised vortex: A topological defect in a superfluid carrying a fixed quantum of circulation around its core.

Two-fluid model: A theoretical framework describing superfluid helium as a mixture of inviscid superfluid and viscous normal components.

Vortex reconnection: A process in which two vortex lines intersect and exchange parts, altering the vortex configuration and enabling energy transfer.

Kolmogorov cascade: A cascade of kinetic energy from large scales to small scales following a universal power-law spectrum in turbulent flow.

Kelvin wave: A helical excitation propagating along a quantised vortex line that mediates energy transfer at small scales.

Mutual friction: The dissipative interaction between the superfluid vortex lines and the normal fluid component.

References

1. Imaging quantized vortex rings in superfluid helium to evaluate quantum dissipation. Nature Communications (2023).
2. Rotating quantum wave turbulence. Nature Physics (2023).
3. Intermittency of Velocity Circulation in Quantum Turbulence. Physical Review X (2021).
4. Dissipation of Quasiclassical Turbulence in Superfluid He4. Physical Review Letters (2015).
5. A new self-consistent approach of quantum turbulence in superfluid helium. The European Physical Journal Plus (2020).