Physicists develop world’s best qubits

Assistant Professor Wesley Campbell, UCLA Physics & Astronomy. Credit: UCLA

A team of researchers at UCLA has set a new record for preparing and measuring the quantum bits, or qubits, inside of a quantum computer without error.

The techniques they have developed make it easier to build quantum computers that outperform classical computers for important tasks, including the design of new materials and pharmaceuticals.

Currently, quantum computers are “Noisy Intermediate-Scale Quantum” (NISQ) devices and are very sensitive to errors. Error in preparation and measurement of qubits is particularly onerous: for 100 qubits, a 1% measurement error means a NISQ device will produce an incorrect answer about 63% of the time.

To address this problem, the team developed a new qubit hosted in a laser-cooled, radioactive barium ion. This “goldilocks ion” has nearly ideal properties for realizing ultra-low error rate quantum devices, with an achieved measurement error rate of about 0.03%, lower than any other quantum technology to date. (

The research is published in npj Quantum Information.