nanomagnets can be stably levitated in an external static magnetic field tagged posts

Cosimo Rusconi (l.) and Oriol Romero-Isart (r.) play with a levitron to illustrate their work on nano magnets.
Credit: IQOQI Innsbruck/M.R.Knabl

Quantum physicists have now shown that, despite Earnshaw’s theorem, nanomagnets can be stably levitated in an external static magnetic field owing to quantum mechanical principles. The quantum angular momentum of electrons, which also causes magnetism, is accountable for this mechanism.

Already in 1842, British mathematician Samuel Earnshaw proved that there is no stable configuration of levitating permanent magnets. If one magnet is levitated above another, the smallest disturbance will cause the system to crash...