Dutch Startup QuantWare to Start Selling Quantum Processors Based on Transmons

(ArsTechnia) Dutch startup QuantWare announced that it will start selling quantum processors based on transmons, superconducting loops of wire that form the basis of similar machines used by Google, IBM, and Rigetti.
Transmon-based qubits are popular because they’re compatible with the standard fabrication techniques used for more traditional processors; they can also be controlled using microwave-frequency signals. Their big downside is that they operate only at temperatures that require liquid helium and specialized refrigeration hardware. These requirements complicate the hardware needed to exchange signals between the very cold processor and the room-temperature hardware that controls it.
Startup companies like D-Wave and Rigetti have set up their own fabrication facilities, but Matthijs Rijlaarsdam, one of QuantWare’s founders, told Ars that his company is taking advantage of an association with TU Delft, the host of the Kavli Nanolab. This partnership lets QuantWare do the fabrication without investing in its own facility. Rijlaarsdam said the situation shouldn’t be a limiting factor, since he expects that the total market likely won’t exceed tens of thousands of processors over the entirety of the next decade. Production volumes don’t have to scale dramatically.