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arXiv · 2304.05086

High-fidelity two-qubit gates of hybrid superconducting-semiconducting singlet-triplet qubits

Maria Spethmann·Stefano Bosco·Andrea Hofmann·Jelena Klinovaja·Daniel Loss
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Abstract

Hybrid systems comprising superconducting and semiconducting materials are promising architectures for quantum computing. Superconductors induce long-range interactions between the spin degrees of freedom of semiconducting quantum dots. These interactions are widely anisotropic when the semiconductor material has strong spin-orbit interactions. We show that this anisotropy is tunable and enables fast and high-fidelity two-qubit gates between singlet-triplet (ST) spin qubits. Our design is immune to leakage of the quantum information into noncomputational states and removes always-on interactions between the qubits, thus resolving key open challenges for these architectures. Our ST qubits do not require additional technologically demanding components nor fine-tuning of parameters. They operate at low magnetic fields of a few millitesla and are fully compatible with superconductors. By suppressing systematic errors in realistic devices, we estimate infidelities below $10^{-3}$, which could pave the way toward large-scale hybrid superconducting-semiconducting quantum processors.

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Maria Spethmann, Stefano Bosco, Andrea Hofmann, Jelena Klinovaja, Daniel Loss. 2023-04-11. High-fidelity two-qubit gates of hybrid superconducting-semiconducting singlet-triplet qubits. https://doi.org/10.1103/physrevb.109.085303

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