A Canadian quantum computing start-up claims its new qubit will enable much smaller and cheaper error-free quantum computers. But getting there will be a steep challenge. To correct its own errors, a traditional computer saves duplicates of information in multiple places, a practice called redundancy. For quantum computers to achieve their own version of redundancy, they typically require many additional quantum bits, or qubits – hundreds of thousands of them. Now, Julien Camirand Lemyre at Nord Quantique and his colleagues have created a qubit that they say will let them slash that number to mere hundreds. “The basic underlying idea behind our hardware is… having qubits that have intrinsic redundancy,” he says. There are several competing versions of qubits, such as tiny superconducting circuits and extremely cold atoms. Nord Quantique’s qubit is a superconducting cavity filled with microwave radiation: the particles that carry this radiation, photons, are trapped inside the cavity where they bounce back and forth, and information can be encoded into their quantum states. Similar qubit designs have been built before, but the new one is the first with “multimode encoding”. This means that the researchers used several of the photon’s properties at once to store information – an encoding method that makes that data more resilient to common quantum computer errors.

Full report : Canadian quantum computing startup, Nord Quantique’s new superconducting cavity filled with microwave radiation can reduce qubit errors dramatically.