2025-12-08 シカゴ大学
By making rare-earth doped crystals using a technique called molecular-beam epitaxy rather than the traditional Czochralski method, the UChicago PME team built components atom by atom with remarkably long-lived quantum coherence.Photo by Jason Smith
＜関連情報＞
- https://news.uchicago.edu/story/breakthrough-could-connect-quantum-computers-200-times-longer-distance
- https://www.nature.com/articles/s41467-025-64780-6
長寿命コヒーレンスを備えたデュアルエピタキシャル通信スピン光子インターフェース Dual epitaxial telecom spin-photon interfaces with long-lived coherence
Shobhit Gupta,Yizhong Huang,Shihan Liu,Yuxiang Pei,Qiang Gao,Shuolong Yang,Natasha Tomm,Richard J. Warburton & Tian Zhong
Nature Communications Published:06 November 2025
DOI:https://doi.org/10.1038/s41467-025-64780-6
Abstract
Optically active solid-state spin qubits thrive as an appealing technology for quantum interconnects and quantum networks, thanks to their atomic size, scalable synthesis, long-lived coherence, and ability to coherently interface with flying qubits. Trivalent erbium dopants, in particular, emerge as an attractive candidate due to their emission in the telecom C band and shielded 4f intra-shell spin and optical transitions. Nevertheless, prevailing top-down architectures for rare-earth qubits and devices have not yet achieved simultaneous long optical and spin coherence, which is necessary for efficient long-distance quantum networks. Here, we demonstrate dual Er3+ telecom spin-photon interfaces in two distinct lattice symmetry sites within an epitaxial thin-film platform. By leveraging high matrix crystallinity, controlled proximity of dopants to surfaces, and exploiting host lattice symmetry, we simultaneously achieve kilohertz-level optical linewidth in a strongly symmetry-protected site, and erbium qubit spin coherence times exceeding 10 milliseconds. Additionally, we realize single-shot readout and microwave coherent control of erbium qubits in a fiber-integrated package, enabling rapid deployment and scalability. These advancements highlight the significant potential of high-quality rare-earth qubits and quantum memories assembled using a bottom-up method, paving the way for scalable development of quantum light-matter interfaces tailored for telecommunication quantum networks.
