Towards scalable silicon quantum computing

Qubits can be made out of a variety of experimental platforms, fig. 1. Small processors have already been demonstrated in trapped ions and superconductors but in both cases, the constraints for coherent manipulation and the effective large size of the qubits including all quantum functionalities are hardly compatible with very large-scale architecture. When it comes to the crucial issue of large-scale integration, Si spin qubits are well positioned due to their long coherence times and compatibility with semiconductor fabrication techniques. Indeed, dephasing times of the order of 1s have been achieved in Si-based spin qubits and single-qubit gate fidelities are high enough for scalable, fault-tolerant quantum computing.