Why the speed of foreign object passing through the superfluid can exceed the critical limit

However, in 2016, researchers at Lancaster University discovered that wires passing through the helium 3 superfluid can exceed the critical speed without destroying the superfluid.

In the subsequent experiments, they measured the force required to pass the wire through the superfluid. When the wire starts to move, there will be a very weak hindering force. But once it starts to move, the required thrust is zero.

In the beginning, when the wire was inserted, the Cooper pair had to be pushed away, so the resistance was measured. When the Cooper pair in the superfluid covers the foreign object, for the superfluid, the moving mass is the superfluid itself, so the stability of the superfluid will not be damaged by the interaction.

Iron ion superfluid can be used to make superconductors, and superconductors are an important part of quantum computers. Knowing more about the mechanism of superfluid may bring us closer to the final application goal.

The research is published in Nature Communications.