Microwave-based quantum control and coherence protection of tin-vacancy spin qubits in a strain-tuned diamond membrane heterostructure

• Main Authors: Guo, Xinghan, Stramma, Alexander M, Li, Zixi, Roth, William G, Huang, Benchen, Jin, Yu, Parker, Ryan A, Martínez, Jesús Arjona, Shofer, Noah, Michaels, Cathryn P, Purser, Carola P, Appel, Martin H, Alexeev, Evgeny M, Liu, Tianle, Ferrari, Andrea C, Awschalom, David D, Delegan, Nazar, Pingault, Benjamin, Galli, Giulia, Heremans, F. Joseph, Atatüre, Mete, High, Alexander A
• Format: Journal Article
• Language: English
• Published: 21-07-2023
• Subjects: Physics - Materials Science; Physics - Mesoscale and Nanoscale Physics; Physics - Quantum Physics
• DOI: 10.48550/arxiv.2307.11916

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) ${\mu}$s 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.