Six days ago, IBM agreed to buy a quantum-computing lab that builds a kind of qubit IBM does not. This week, the lab showed the world why.
HRL Laboratories published a result in Nature on Wednesday: a silicon quantum processor that, in effect, runs itself. The Malibu research house is jointly owned by Boeing and General Motors. IBM had agreed to acquire it on 23 July, before the paper was public.
The wiring problem
Every quantum computer hits the same scaling trap. The qubits sit in a refrigerator near absolute zero. The electronics that control them sit at room temperature, in racks. Each qubit needs its own control lines running down into the cold. Scale to the millions of qubits a useful machine will need, and the wiring becomes an impossible tangle.
HRL moved the controller into the cold. It built a custom chip that runs at about 4 kelvin, inside the fridge beside the qubits. That chip generated every control signal for an 18-qubit device. Crucially, it ran error correction on its own, with no real-time help from room-temperature electronics, the company said. HRL says that is a first.
