Abstract
The scalability of Si manufacturing technologies and the ease of manipulation via electric-dipole spin resonance make hole spin qubits in SiMOS quantum dots an attractive physical platform for the development of quantum processors. Devices consisting of small-scale dot arrays fabricated with 300 mm Fully Depleted Silicon On Insolator (FDSOI) technology, have demonstrated the viability of this approach. While single qubit operations are now routinely achieved, the control of exchange coupling remains challenging, yet it is essential for implementing the two qubit operations required for a universal quantum computer.

In this thesis, we investigate a new generation of hole SiMOS device, with gate-defined quantum dots in Si nanowires, and attempt to measure and control exchange interaction between hole spin in neighboring quantum dots. This new line of device employs a second gate layer interleaved between the first gate layer, obtained with small deviations of an established CMOS fabrication flow. This additional gate layer is expected to provide improved control over the dot positions and their interdot tunnel coupling.

We first characterize the operation of few-holes dots in single-nanowire devices, with four linear quantum dots. To overcome the limitations of this design regarding the coupling of few-hole dots, we then investigate devices of a novel geometry, composed of two parallel nanowires. In these, we demonstrate charge sensing between a Single Hole Box (SHB) operated in a first nanowire, and a few-hole dot operated in the second. After benchmarking this remote charge sensor, we then employ this measurement scheme to probe isolated double quantum dots. In this configuration, we demonstrate reproducible loading of a given number of holes, tunable tunnel coupling, and Pauli Spin Blockade (PSB).