2023-11-30 アルゴンヌ国立研究所(ANL)
◆この手法により、qubitsの操作温度が上昇し、冷却に必要なリソースが削減され、設備および運用コストが大幅に削減されました。同時に、新しいシステムにより、マイクロ波を使用してqubitsを制御でき、信頼性が向上しました。これにより、将来の量子ネットワークの構築がより実現可能になりました。研究はQ-NEXT量子研究センターの支援を受けており、物理学ジャーナル「Physical Review X」にて発表されました。
＜関連情報＞
- https://www.anl.gov/article/researchers-invent-new-way-to-stretch-diamond-for-better-quantum-bits
- https://journals.aps.org/prx/abstract/10.1103/PhysRevX.13.041037
ひずみ調整されたダイヤモンド膜ヘテロ構造におけるスズ空孔スピンキュービットのマイクロ波ベースの量子制御とコヒーレンス保護 Microwave-Based Quantum Control and Coherence Protection of Tin-Vacancy Spin Qubits in a Strain-Tuned Diamond-Membrane Heterostructure
Xinghan Guo, Alexander M. Stramma, Zixi Li, William G. Roth, Benchen Huang, Yu Jin, Ryan A. Parker, Jesús Arjona Martínez, Noah Shofer, Cathryn P. Michaels, Carola P. Purser, Martin H. Appel, Evgeny M. Alexeev, Tianle Liu, Andrea C. Ferrari, David D. Awschalom, Nazar Delegan, Benjamin Pingault, Giulia Galli, F. Joseph Heremans, Mete Atatüre, and Alexander A. High
Physical Review X Published 29 November 2023
DOI:https://doi.org/10.1103/PhysRevX.13.041037
ABSTRACT
Robust spin-photon interfaces in solids are essential components in quantum networking and sensing technologies. Ideally, these interfaces combine a long-lived spin memory, coherent optical transitions, fast and high-fidelity spin manipulation, and straightforward device integration and scaling. The tin-vacancy center (SnV) in diamond is a promising spin-photon interface with desirable optical and spin properties at 1.7 K. However, the SnV spin lacks efficient microwave control, and its spin coherence degrades with higher temperature. In this work, we introduce a new platform that overcomes these challenges—SnV centers in uniformly strained thin diamond membranes. The controlled generation of crystal strain introduces orbital mixing that allows microwave control of the spin state with 99.36(9)% gate fidelity and spin coherence protection beyond a millisecond. Moreover, the presence of crystal strain suppresses temperature-dependent dephasing processes, leading to a considerable improvement of the coherence time up to 223(10) μs at 4 K, a widely accessible temperature in common cryogenic systems. Critically, the coherence of optical transitions is unaffected by the elevated temperature, exhibiting nearly lifetime-limited optical linewidths. Combined with the compatibility of diamond membranes with device integration, the demonstrated platform is an ideal spin-photon interface for future quantum technologies.
