Investigating Effects of Gamma Radiation on Spin Qubits in HRL SLEDGE Devices

Spin qubits have seen much progress over recent years, proving to be an appealing candidate for scalable quantum computing with small footprints, electrical control, promising coherence times, and the industry-compatible silicon material platform. As advances are made in the spaces of control and scaling, addressing noise from various origins becomes increasingly pertinent. It has been shown that cosmic rays can cause bit flips and correlated errors in superconducting qubits [1]; however, similar effects in spin qubits have never been reported or studied in literature. To characterize the effects of ionizing radiation, we use Si/SiGe SLEDGE devices from HRL, as a part of the Qubits for Computing Foundry, irradiating them with a Cs-137 gamma source. We investigate the effects of ionizing radiation on the charge sensing dots using Coulomb-blockade peaks. We record significant drifts in position as a function of radiation dose as well as an increase in noise that stays even after removing the source. We perform additional measurements to further understand the effects on the device and on qubit operation. These experiments should provide insights into the effects of environmental radiation on spin qubit devices.

[1] Li, X., Wang, J., Jiang, YY. et al. Cosmic-ray-induced correlated errors in superconducting qubit array. Nat Commun 16, 4677 (2025)