## Scientists Measure Magnetic Interaction Between Two Bound Electrons 26

An anonymous reader writes

*In a paper published in**Nature*(abstract), scientists report successfully measuring the magnetic interaction of two bound electrons of two different strontium (Sr) ions. The two ions were suspended in a quadrupole ion trap (a.k.a. a Paul trap), and the effects of ambient magnetic noise were mitigated by 'restricting the spin evolution [of the electrons] to a decoherence-free subspace that is immune to collective magnetic field noise.' The scientists measured the magnetic interaction of the two electrons as a function of distance and found that the force acting between the two was inversely dependant on the cubed distance between the electrons, consistent with Newton's inverse-cube law.
## Ingress is unclear: not inverse cube force (Score:3, Informative)

From ingress

"the force acting between the two was inversely dependant on the cubed distance between the electrons"This should not be understood as inverse cube force between the electrons. From article:"By varying the separation between the two ions, they were able to measure the strength of the magnetic interaction as a function of distance – confirming the expected inverse-cubic (1/d3) dependence of the interaction."It is the strength of the interaction that is found to be inverse cubic. The strength of magnetic force is inverse quadratic. If somebody found evidence of an inverse cubic force then this would be evidence of higher-spatial dimensions and very unexpected indeed. There has been speculation that gravity might be higher-dimensional at very small scales, but I have never heard anyone make this claim of of electromagnetic forces. The cross-product nature of the electric/magnetic interaction makes these forces a true child of an 3 dimensional space.

## Observing two spins IS the big technological leap (Score:3, Informative)