Researchers at MIT Achieve 99.998% Single Qubit Gate Fidelity on a Superconducting Qubit

MIT researchers achieved a record single-qubit fidelity for superconducting based quantum processors of 99.998% using a superconducting qubit called fluxonium. Although ion trapped based qubits have been able to reach this level, this is the highest we have seen for a qubit based upon superconducting technology. The researchers developed two new control techniques to combat errors, particularly counter-rotating errors, which arise when qubits are controlled with electromagnetic waves. The researchers created “commensurate pulses,” applying them at precisely timed intervals to make errors consistent and correctable. This advancement builds on earlier ideas like circularly polarized microwave drives.

Fluxonium qubits, which include a large “superinductor,” show promise due to their high coherence and lower error rates. The researchers’ techniques enhance quantum gate fidelity, essential for practical quantum computing. These methods are expected to be useful for high-fidelity control in various quantum computing platforms, contributing to the goal of fault-tolerant quantum computing.

For more about this research, view a news posting on the MIT website here and also a technical article available at PRX Quantum here.

January 18, 2025