Cujia K S, Herb K, Zopes J, Abendroth J M, Degen C L
Department of Physics, ETH Zurich, Otto Stern Weg 1, 8093, Zurich, Switzerland.
IT'IS Foundation, Zeughausstrasse 43, 8004, Zurich, Switzerland.
Nat Commun. 2022 Mar 10;13(1):1260. doi: 10.1038/s41467-022-28935-z.
Nuclear magnetic resonance imaging (MRI) at the atomic scale offers exciting prospects for determining the structure and function of individual molecules and proteins. Quantum defects in diamond have recently emerged as a promising platform towards reaching this goal, and allowed for the detection and localization of single nuclear spins under ambient conditions. Here, we present an efficient strategy for extending imaging to large nuclear spin clusters, fulfilling an important requirement towards a single-molecule MRI technique. Our method combines the concepts of weak quantum measurements, phase encoding and simulated annealing to detect three-dimensional positions from many nuclei in parallel. Detection is spatially selective, allowing us to probe nuclei at a chosen target radius while avoiding interference from strongly-coupled proximal nuclei. We demonstrate our strategy by imaging clusters containing more than 20 carbon-13 nuclear spins within a radius of 2.4 nm from single, near-surface nitrogen-vacancy centers at room temperature. The radius extrapolates to 5-6 nm for H. Beside taking an important step in nanoscale MRI, our experiment also provides an efficient tool for the characterization of large nuclear spin registers in the context of quantum simulators and quantum network nodes.
原子尺度的核磁共振成像（MRI）为确定单个分子和蛋白质的结构与功能提供了令人兴奋的前景。金刚石中的量子缺陷最近已成为实现这一目标的一个有前景的平台，并能在环境条件下实现单核自旋的检测与定位。在此，我们提出一种将成像扩展至大核自旋簇的有效策略，满足了单分子MRI技术的一项重要要求。我们的方法结合了弱量子测量、相位编码和模拟退火的概念，以并行方式从多个原子核检测三维位置。检测具有空间选择性，使我们能够在选定的目标半径处探测原子核，同时避免来自强耦合近端原子核的干扰。我们通过在室温下对距单个近表面氮空位中心半径2.4纳米范围内包含20多个碳 - 13核自旋的簇进行成像来证明我们的策略。对于氢，该半径外推至5 - 6纳米。除了在纳米级MRI方面迈出重要一步外，我们的实验还为在量子模拟器和量子网络节点背景下表征大核自旋寄存器提供了一种有效工具。
