A new dissipator lowers qubit temperature by 14 millikelvin

Researchers at the Beijing Key Laboratory of Fault-Tolerant Quantum Computing and the Hefei National Laboratory have achieved a qubit reset error rate of 0.0028, a substantial reduction that brings scalable quantum computing closer to reality. The team demonstrated this improvement using a compact on-chip dissipator operating below the qubit frequency, a counterintuitive approach that lowers the effective temperature of the qubit from 49 mK to 35 mK. This new reset protocol is robust to parameter variations, simplifying the calibration process for large-scale superconducting quantum processors. A process error of 0.0028 has been achieved in resetting a superconducting qubit, a substantial reduction enabled by a newly designed on-chip dissipator operating below the qubit’s resonant frequency. This level of fidelity represents a critical step toward building larger, more reliable quantum processors where rapid and accurate qubit re-initialization is paramount. The device minimizes disruption to qubit coherence while efficiently…