Coupling control in the few-electron regime of quantum dot arrays using 2-metal gate levels in CMOS technology

Scalability is one of the biggest advantages of silicon spin qubits over other platforms, making them very promising candidates in the quest for quantum computing. In this work we approach the regime of interest for large-scale qubit integration, showing that we can deliver high electrostatic coupling control and individual tunability over an array of quantum dots (QDs). To do this we use FDSOI devices fabricated with 2-metal gate levels in an industry-compatible CMOS process. We operate them at 100mK, and in a dot-configuration where large control on tunnel barriers is leveraged. In the many-electron regime, we observe the transition of quantum dot array from single- to triple-dot configurations. Moreover, in the few-electron regime, we demonstrate the effective and in-situ modulation of the tunnel coupling between two adjacent QDs.