Frozen operation of FDSOI Quantum Devices

Silicon spin qubits offer a robust platform for scaling up quantum processors using industrial CMOS technology. We investigate the physics and measurement techniques of spin qubits fabricated in a 300 mm FDSOI CMOS process, focusing on the characterization of tunnel coupling and spin readout. Using DC single-electron transistor sensors combined with fast voltage pulsing, we quantify tunnel coupling spanning from the GHz regime to 10⁻⁵ Hz, demonstrating accurate and reproducible control of tunnel barriers suitable for coherent spin manipulation [1, 2]. To disentangle charge and spin dynamics, we implement a frozen Pauli spin blockade scheme [3] that allows independent optimization of charge readout sensitivity and spin projection fidelity, suppressing unwanted relaxation pathways.