Readout sweet spots for spin qubits with strong spin-orbit interaction

• URL: http://arxiv.org/abs/2505.15878v1
• Date: Wed, 21 May 2025 17:54:48 GMT
• Title: Readout sweet spots for spin qubits with strong spin-orbit interaction
• Authors: Domonkos Svastits, Bence Hetényi, Gábor Széchenyi, James Wootton, Daniel Loss, Stefano Bosco, András Pályi,
• Abstract summary: We model charge-sensing-based readout for semiconductor spin qubits in double quantum dots.<n>We quantify how the charge noise of the sensor, residual tunneling, and $g$-tensor modulation degrade readout fidelity.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Qubit readout schemes often deviate from ideal projective measurements, introducing critical issues that limit quantum computing performance. In this work, we model charge-sensing-based readout for semiconductor spin qubits in double quantum dots, and identify key error mechanisms caused by the back-action of the charge sensor. We quantify how the charge noise of the sensor, residual tunneling, and $g$-tensor modulation degrade readout fidelity, induce a mixed post-measurement state, and cause leakage from the computational subspace. For state-of-the-art systems with strong spin-orbit interaction and electrically tunable $g$-tensors, we identify a readout sweet spot, that is, a special device configuration where readout is closest to projective. Our framework provides a foundation for developing effective readout error mitigation strategies, with broad applications for optimizing readout performance for a variety of charge-sensing techniques, advancing quantum protocols, and improving adaptive circuits for error correction.

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