A single hole spin with enhanced coherence in natural silicon

Operation sweet spots decouple hole spin qubits in silicon from charge noise while conserving full electrical control and allowing for spin coherence times of up to 88 mu s. Semiconductor spin qubits based on spin-orbit states are responsive to electric field excitations, allowing for practical, fast and potentially scalable qubit control. Spin electric susceptibility, however, renders these qubits generally vulnerable to electrical noise, which limits their coherence time. Here we report on a spin-orbit qubit consisting of a single hole electrostatically confined in a natural silicon metal-oxide-semiconductor device. By varying the magnetic field orientation, we reveal the existence of operation sweet spots where the impact of charge noise is minimized while preserving an efficient electric-dipole spin control. We correspondingly observe an extension of the Hahn-echo coherence time up to 88 mu s, exceeding by an order of magnitude existing values reported for hole spin qubits, and approaching the state-of-the-art for electron spin qubits with synthetic spin-orbit coupling in isotopically purified silicon. Our finding enhances the prospects of silicon-based hole spin qubits for scalable quantum information processing.

Automated summary

This article reports a spin-orbit hole spin qubit, which achieves operation sweet spots by varying the magnetic field direction, reducing charge noise and extending Hahn-echo coherence time, providing new possibilities for the scalability of silicon-based hole spin qubits in quantum information processing.