Multi-Scale Simulation Framework for the Modelling of Charge Capture and Emission in Spin Qubit Devices

Charge transfer events can degrade the performance of spin qubits by inducing instabilities and decoherence. We present a multi-scale simulation approach to model these transitions and quantify their impact on qubit properties. Applying this framework to hole transfer between hydrogen bridge defects in SiO2 and nearby gates, we find that, while their slow dynamics and large electrostatic impact rule them out as the main source of charge-noise-driven decoherence, such events can account for observed device instabilities.