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

Fuente: arXiv
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Main Authors: Svastits, Domonkos, Hetényi, Bence, Széchenyi, Gábor, Wootton, James, Loss, Daniel, Bosco, Stefano, Pályi, András
Format: Preprint
Published: 2025
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author Svastits, Domonkos
Hetényi, Bence
Széchenyi, Gábor
Wootton, James
Loss, Daniel
Bosco, Stefano
Pályi, András
author_facet Svastits, Domonkos
Hetényi, Bence
Széchenyi, Gábor
Wootton, James
Loss, Daniel
Bosco, Stefano
Pályi, András
contents 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.
format Preprint
id arxiv_https___arxiv_org_abs_2505_15878
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Readout sweet spots for spin qubits with strong spin-orbit interaction
Svastits, Domonkos
Hetényi, Bence
Széchenyi, Gábor
Wootton, James
Loss, Daniel
Bosco, Stefano
Pályi, András
Quantum Physics
Mesoscale and Nanoscale Physics
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.
title Readout sweet spots for spin qubits with strong spin-orbit interaction
topic Quantum Physics
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2505.15878