# Our new paper published as a PRL Editors Suggestion

Counterflow-Induced Inverse Energy Cascade in Three-Dimensional Superfluid Turbulence

Superfluids are characterised by being described by an immiscible mixture of two fluids: a *normal fluid*, that is viscous and a *superfluid* with no viscosity. When a superfluid is heated on one side of a channel, the normal fluid carries the heat away, and the superfluid flows in the opposite direction to conserve the mass. Such a situation generates an out-of-equilibrium state where the two fluids have a non-zero mean relative velocity, known as counterflow. In this work, we showed that for very large counterflow, a three-dimensional superfluid abruptly becomes quasi-two-dimensional and displays all the phenomenology of two-dimensional turbulent flows.

The figure above shows a visualisation of the vorticity field for both, the superfluid and the normal components. On the left, there is no counterflow and the system is fully three-dimensional. On the right, a strong counterflow is applied and the system becomes quasi-two-dimensional.

Learn more about this work in the publication below.