Ballast charges for semiconductor spin qubits

Semiconductor spin qubits hold great promise for quantum computing, but their performance is hindered by fluctuating electromagnetic environments. We propose a novel solution using ballast charges, induced charges on a screening layer beneath the qubits. These charges counteract fluctuations from two-level systems, reducing the charge noise power spectral density. Simulations show a 4–6x improvement in spin qubit dephasing times in Si/SiGe devices. We will also discuss practical challenges and potential solutions for implementing this method.