Single-electron control in a foundry-fabricated 2D array of silicon quantum dots

Two-dimensional quantum dot arrays constitute a useful platform for spin-qubit processors and condensed matter simulations. With the advent of foundry-fabricated silicon qubits [1], larger CMOS quantum dot arrays become increasingly promising for implementing multi-qubit devices. We use a 2x2 array of quantum dots, fabricated fully at CEA-LETI using industrial silicon-on-insulator technology, to reconfigure the array as single, double, triple, or quadruple dots, and use dispersive charge sensing to deplete all dots down to the last electron. Combining high-frequency reflectometry with pulsed-gate techniques, we tune tunneling rates and demonstrate the shuttling of individual electrons within the two-dimensional array.

[1] Maurand, R. et al. A CMOS silicon spin qubit. NatureCommunications 7, 13575 (2016).