Electron-spin qubits have long coherence times suitable for quantum technologies. Spin–orbit coupling promises to greatly improve spin qubit scalability and functionality, allowing qubit coupling via photons, phonons or mutual capacitances, and enabling the realization of engineered hybrid and topological quantum systems. However, despite much recent interest, results to date have yielded short coherence times (from 0.1 to 1 μs). Here we demonstrate ultra-long coherence times of 10 ms for holes where spin–orbit coupling yields quantized total angular momentum. We focus on holes bound to boron acceptors in bulk silicon 28, whose wavefunction symmetry can be controlled through crystal strain, allowing direct control over the longitudinal electric dipole that causes decoherence. The results rival the best electron-spin qubits and are 10⁴ to 10⁵ longer than previous spin–orbit qubits. These results open a pathway to develop new artificial quantum systems and to improve the functionality and scalability of spin-based quantum technologies.

电子自旋量子位具有很长的相干时间，适合于量子技术。自旋-轨道耦合有望大大改善自旋量子位的可扩展性和功能性，允许通过光子，声子或互电容进行量子位耦合，并实现工程化的混合和拓扑量子系统。然而，尽管最近有很多兴趣，但迄今为止的结果产生了较短的相干时间（从0.1到1μs）。在这里，我们证明了自旋轨道耦合产生量化的总角动量的孔的超长相干时间为10 ms。我们关注于与体硅28中硼受体结合的空穴，可以通过晶体应变控制其波函数对称性，从而可以直接控制引起去相干的纵向电偶极子。结果与最佳的电子自旋量子比特相当，为10比以前的自旋轨道量子位长⁴至10 ⁵。这些结果为开发新的人工量子系统以及改善自旋量子技术的功能和可扩展性开辟了道路。