Active Leakage Cancellation in Single Qubit Gates

• URL: http://arxiv.org/abs/2503.14731v2
• Date: Fri, 26 Sep 2025 20:54:16 GMT
• Title: Active Leakage Cancellation in Single Qubit Gates
• Authors: Ben Chiaro, Yaxing Zhang,
• Abstract summary: We enhance the state-of-the-art single qubit gate by introducing active leakage cancellation.<n>We apply the technique to superconducting transmon qubits, suppressing the leakage below the $10-5$ level.
• Score: 0.05342730996459061
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: The ability to perform fast and accurate rotations between the computational basis states of quantum bits is one of the most fundamental requirements for building a quantum computer. Because physical qubits generally contain more than two levels, faster gates often result in a higher leakage rate outside of the computational space. In this letter, we enhance the state-of-the-art single qubit gate by introducing active leakage cancellation. This is accomplished via a second drive tone near the leakage transition such that we cancel the leakage caused by the main drive. Furthermore, we describe a measurement sequence that can be used to calibrate the parameters of this leakage cancellation drive. Finally, we apply the technique to superconducting transmon qubits, suppressing the leakage below the $10^{-5}$ level, and achieving coherence-limited gate infidelity of $7.5\times 10^{-5}$, for a 10 ns $\pi/2$ gate and 196 MHz qubit anharmonicity.

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