According to the University of Cambridge
The challenge was to confine electrons tightly in a ‘quantum wire’ and bring this wire close enough to an ordinary metal so that the electrons in that metal could ‘jump’ by quantum tunneling into the wire. By observing how the rate of jumping varies with an applied magnetic field the experiment reveals how the electron, on entering the quantum wire, has to fall apart into spinons and holons.
The press release quotes Andy Schofield that
What is remarkable about this new experiment is not just the clarity of the observation of the spinon and holon, which confirms some earlier studies, but that the spinon and holon are seen well beyond the region that Duncan Haldane originally conjectured.
For a full report see here.