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arXiv · 2505.00769

Quasiparticle-induced decoherence of a driven superconducting qubit

Mykola Kishmar·Pavel D. Kurilovich·Andrey Klots·Thomas Connolly·Igor L. Aleiner·Vladislav D. Kurilovich
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Abstract

We develop a theory for two quasiparticle-induced decoherence mechanisms of a driven superconducting qubit. In the first mechanism, an existing quasiparticle (QP) tunnels across the qubit's Josephson junction while simultaneously absorbing a qubit excitation and one (or several) photons from the drive. In the second mechanism, a qubit transition occurs during the non-linear absorption process converting multiple drive quanta into a pair of new QPs. Both mechanisms can remain significant in gap engineered qubits whose coherence is insensitive to QPs without the drive. Our theory establishes a fundamental limitation on fidelity of the microwave qubit operations, such as readout and gates, stemming from QPs.

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Mykola Kishmar, Pavel D. Kurilovich, Andrey Klots, Thomas Connolly, Igor L. Aleiner, Vladislav D. Kurilovich. 2025-05-01. Quasiparticle-induced decoherence of a driven superconducting qubit. https://doi.org/10.1103/3q5z-tk7c

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