Under the application of a weak static magnetic field, this ring-shaped ion crystal
will begin a rotation that will never stop.
They found that applying a force in the appropriate direction increased the distance between ion layers in a different direction, confirming that an ion crystal
can exhibit a negative Poisson's ratio without a change in volume.
Strong collective coupling has been shown with neutral atoms and 3d ion crystals
, But has not been performed in a system with individual-qubit control and coulomb-mediated entanglement capabilities.