Gritsch Andreas, Ulanowski Alexander, Pforr Jakob, Reiserer Andreas
TUM School of Natural Sciences, Department of Physics and Munich Center for Quantum Science and Technology (MCQST), Technical University of Munich, James-Franck-Str. 1, Garching, Germany.
Max-Planck-Institute of Quantum Optics, Hans-Kopfermann-Str. 1, Garching, Germany.
Nat Commun. 2025 Jan 2;16(1):64. doi: 10.1038/s41467-024-55552-9.
Small registers of spin qubits in silicon can exhibit hour-long coherence times and exceeded error-correction thresholds. However, their connection to larger quantum processors is an outstanding challenge. To this end, spin qubits with optical interfaces offer key advantages: they can minimize the heat load and give access to modular quantum computing architectures that eliminate cross-talk and offer a large connectivity. Here, we implement such an efficient spin-photon interface based on erbium dopants in a nanophotonic resonator. We demonstrate optical single-shot readout of a spin in silicon whose coherence exceeds the Purcell-enhanced optical lifetime, paving the way for entangling remote spins via photon interference. As erbium dopants can emit coherent photons in the minimal-loss band of optical fibers, and tens of such qubits can be spectrally multiplexed in each resonator, the demonstrated hardware platform offers unique promise for distributed quantum information processing based on scalable, integrated silicon devices.
硅基自旋量子比特的小型寄存器可展现长达数小时的相干时间，且超过了纠错阈值。然而，将它们与更大规模的量子处理器相连接仍是一项严峻挑战。为此，具备光学接口的自旋量子比特具有关键优势：它们能够将热负载降至最低，并接入模块化量子计算架构，从而消除串扰并提供大规模连接性。在此，我们基于纳米光子谐振器中的铒掺杂剂实现了这样一种高效的自旋 - 光子接口。我们展示了对硅中自旋的光学单次读出，其相干性超过了珀塞尔增强光学寿命，为通过光子干涉纠缠远程自旋铺平了道路。由于铒掺杂剂可在光纤的最低损耗波段发射相干光子，并且每个谐振器中可对数十个此类量子比特进行光谱复用，所展示的硬件平台为基于可扩展集成硅器件的分布式量子信息处理提供了独特的前景。
