That doesn’t mean the error-corrected qubit was fully stable. Eventually, one of the errors that inevitably occurred couldn’t be recovered from because too many of its individual atoms changed state at once. But performing normal error correction could keep some of these logical qubits stable for up to 90 rounds.
Again, that’s not good enough for any sort of sophisticated calculation. But it’s a lot closer than the company was before working out this technique.
Resonating
EeroQ is a startup with a distinct approach to qubits. A number of companies are looking into using the spin of electrons as their qubits, typically because it’s easy to fabricate chips that can manipulate electrons held in quantum dots. EeroQ is making its chips with lots of tiny pools that can hold a drop of liquid helium. When an electron is placed on that drop, it has nowhere to go because helium hates to carry an extra electron. So, the lone electron just floats on the surface.
Which is great, but it was already well-established physics long before the company launched. The problem was that nobody had figured out a method to interact with the electron in useful ways.
Recently, the company released a manuscript describing a new version of its chip, one with a small resonator next to the helium-filled pool. They showed that this resonator could couple with the movement of the electron, which is kept from hitting the walls of the pool by an electrical field. Since the electron’s motional states are quantized, the resonator adopts one or two states during the experimental procedure, which is the potential building block of a qubit.
Again, that’s nowhere near having functional computing hardware. But again, it’s this sort of incremental work that’s needed if any of these technologies is going to live up to its promise.
