Eisenach Erik R, Barry John F, O'Keeffe Michael F, Schloss Jennifer M, Steinecker Matthew H, Englund Dirk R, Braje Danielle A
Massachusetts Institute of Technology, Cambridge, MA, USA.
MIT Lincoln Laboratory, Lexington, MA, USA.
Nat Commun. 2021 Mar 1;12(1):1357. doi: 10.1038/s41467-021-21256-7.
Overcoming poor readout is an increasingly urgent challenge for devices based on solid-state spin defects, particularly given their rapid adoption in quantum sensing, quantum information, and tests of fundamental physics. However, in spite of experimental progress in specific systems, solid-state spin sensors still lack a universal, high-fidelity readout technique. Here we demonstrate high-fidelity, room-temperature readout of an ensemble of nitrogen-vacancy centers via strong coupling to a dielectric microwave cavity, building on similar techniques commonly applied in cryogenic circuit cavity quantum electrodynamics. This strong collective interaction allows the spin ensemble's microwave transition to be probed directly, thereby overcoming the optical photon shot noise limitations of conventional fluorescence readout. Applying this technique to magnetometry, we show magnetic sensitivity approaching the Johnson-Nyquist noise limit of the system. Our results pave a clear path to achieve unity readout fidelity of solid-state spin sensors through increased ensemble size, reduced spin-resonance linewidth, or improved cavity quality factor.
对于基于固态自旋缺陷的设备而言，克服不良读出是一项日益紧迫的挑战，特别是考虑到它们在量子传感、量子信息和基础物理测试中的迅速应用。然而，尽管在特定系统中取得了实验进展，但固态自旋传感器仍缺乏一种通用的、高保真的读出技术。在此，我们基于低温电路腔量子电动力学中常用的类似技术，通过与介电微波腔的强耦合，展示了对氮空位中心系综的高保真室温读出。这种强集体相互作用使得能够直接探测自旋系综的微波跃迁，从而克服了传统荧光读出中光学光子散粒噪声的限制。将该技术应用于磁力测量，我们展示了接近系统约翰逊 - 奈奎斯特噪声极限的磁灵敏度。我们的结果为通过增加系综规模、减小自旋共振线宽或提高腔品质因数来实现固态自旋传感器的统一读出保真度铺平了一条清晰的道路。
