A CMOS silicon hole spin qubit*

Hole spins in silicon represent a promising direction for solid-state quantum computation, possibly combining fast qubits [1] with limited hyperfine interaction. We report on a qubit device implemented on a foundry-compatible Si CMOS platform [2]. The device, fabricated using SOI NanoWire MOSFET technology, is in essence a two-gate pFET. The qubit is encoded in the spin degree of freedom of a hole quantum dot defined by one of the gates, while the second gate defines another quantum dot used for the qubit initialization and readout. All electrical, two-axis control of the spin qubit is achieved by applying a phase-tunable microwave modulation to one of the gate. We demonstrate fast coherent oscillations with Rabi frequencies as high as 80MHz with an inhomogeneous dephasing time of T$_{2}^{\ast \, }$\textasciitilde 60ns [3]. By demonstrating a hole spin qubit functionality in a conventional transistor-like layout and process flow, this result bears relevance for the future up-scaling of qubit architectures. [1]- Voisin, B. \textit{et al.} \textit{Nano Lett.} \textbf{16,} 88--92 (2016). [2]- Hutin, L. \textit{et al.} \textit{IEEE Symp. VLSI Technol.} 1--2 (2016). [3]- Maurand, R. \textit{et al.} \textit{Arxiv Prepr. arXiv1605.07599v1} (2016).