I worked in a lab for a bit that was doing this sort of thing, and it's worth saying that Martinis is a genius. The stuff he's doing is far beyond what other groups are doing, and he manages to pull it off in incredibly elegant ways.<p>Coupling two qubits like this is impressive, to say the least. Planar qubits have the advantage of scale when it comes to fabrication, so if this group can figure out how to push entanglement to 3, 4, or more devices, they'll have a huge advantage over other technologies (e.g. ion trapping).