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arXiv · 2312.04321

Universal flux-based control of a $\pi$-SQUID

J. Wilson Staples·Thomas B. Smith·Andrew C. Doherty
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Abstract

We describe a protocol for the universal control of non-ideal $\pi$-periodic superconducting qubits. Our proposal relies on a $\pi$-SQUID: a superconducting loop formed by two $\pi$-periodic circuit elements, with an external magnetic flux threading the circuit. The system exhibits an extensive sweet spot around half-flux where residual $2\pi$-periodic Cooper pair tunneling is highly suppressed. We demonstrate that universal single-qubit operations can be realised by tuning the flux adiabatically and diabatically within this broad sweet spot. We also assess how residual $2\pi$-periodicity in $\pi$-SQUIDs impacts holonomic phase gates.

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J. Wilson Staples, Thomas B. Smith, Andrew C. Doherty. 2023-12-07. Universal flux-based control of a $\pi$-SQUID. https://arxiv.org/abs/2312.04321

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