*IEEE Journal on Multiscale and Multiphysics Computational Techniques*, 2024.

Solid-state spin qubits have emerged as promising quantum information platforms but are susceptible to magnetic noise. Despite extensive efforts in controlling noise in spin qubit quantum applications, one important but less controlled noise source is near-field electromagnetic fluctuations. Low-frequency (MHz and GHz) electromagnetic fluctuations are significantly enhanced near nanostructured lossy material components essential in quantum applications, including metallic/superconducting gates necessary for controlling spin qubits in quantum computing devices and materials/nanostructures to be probed in quantum sensing. Although controlling this low-frequency electromagnetic fluctuation noise is crucial for improving the performance of quantum sensing and computing, current efforts are hindered by computational challenges. In this paper, we leverage advanced computational electromagnetics techniques, especially fast and accurate volume integral equation based solvers, to overcome the computational obstacle. We introduce a theoretical framework to control low-frequency magnetic fluctuation noise for enhancing spin qubit quantum sensing and computing performance. Our framework extends the application of computational electromagnetics to spin qubit quantum devices. We further apply our theoretical framework to control noise effects in realistic quantum computing devices and quantum sensing applications. Our work paves the way for device engineering to control magnetic fluctuations and improve the performance of spin qubit quantum sensing and computing.

**See also:**Quantum Detectors & Sensors