Defects in SiO₂: A Potential Candidate for Charge Noise in Si-Based Quantum Dot Architectures

Quantum dot architectures utilizing silicon-based materials are promising candidates for spin qubits, offering long coherence times, and scalability with well-established fabrication techniques. However, the fidelity of qubit gates is constrained by low-frequency (1/f) charge noise, the origin of which remains poorly understood. High-level theoretical approaches, such as ab initio modeling, are essential for uncovering the mechanisms behind this charge noise. In this talk, we will discuss various defect candidates in oxide dielectrics which could be the source of this charge noise. We will present details of the calculated defect properties, including charge transition levels and local structural configurations, and the effects of structural relaxation on the calculated transition levels.