Wang Guoqing, Li Changhao, Tang Hao, Li Boning, Madonini Francesca, Alsallom Faisal F, Calvin Sun Won Kyu, Peng Pai, Villa Federica, Li Ju, Cappellaro Paola
Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139.
Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139.
Proc Natl Acad Sci U S A. 2023 Aug 8;120(32):e2305621120. doi: 10.1073/pnas.2305621120. Epub 2023 Aug 1.
Solid-state defects are attractive platforms for quantum sensing and simulation, e.g., in exploring many-body physics and quantum hydrodynamics. However, many interesting properties can be revealed only upon changes in the density of defects, which instead is usually fixed in material systems. Increasing the interaction strength by creating denser defect ensembles also brings more decoherence. Ideally one would like to control the spin concentration at will while keeping fixed decoherence effects. Here, we show that by exploiting charge transport, we can take some steps in this direction, while at the same time characterizing charge transport and its capture by defects. By exploiting the cycling process of ionization and recombination of NV centers in diamond, we pump electrons from the valence band to the conduction band. These charges are then transported to modulate the spin concentration by changing the charge state of material defects. By developing a wide-field imaging setup integrated with a fast single photon detector array, we achieve a direct and efficient characterization of the charge redistribution process by measuring the complete spectrum of the spin bath with micrometer-scale spatial resolution. We demonstrate a two-fold concentration increase of the dominant spin defects while keeping the of the NV center relatively unchanged, which also provides a potential experimental demonstration of the suppression of spin flip-flops via hyperfine interactions. Our work paves the way to studying many-body dynamics with temporally and spatially tunable interaction strengths in hybrid charge-spin systems.
固态缺陷是量子传感和模拟的有吸引力的平台，例如，用于探索多体物理和量子流体动力学。然而，许多有趣的特性只有在缺陷密度发生变化时才能揭示出来，而缺陷密度在材料系统中通常是固定的。通过创建更密集的缺陷集合来增加相互作用强度也会带来更多的退相干。理想情况下，人们希望在保持固定退相干效应的同时随意控制自旋浓度。在这里，我们表明，通过利用电荷传输，我们可以在这个方向上迈出一些步伐，同时表征电荷传输及其被缺陷捕获的过程。通过利用金刚石中NV中心的电离和复合循环过程，我们将电子从价带泵浦到导带。然后，这些电荷通过改变材料缺陷的电荷状态来传输，以调制自旋浓度。通过开发一种与快速单光子探测器阵列集成的宽场成像装置，我们通过以微米级空间分辨率测量自旋浴的完整光谱，实现了对电荷重新分布过程的直接和有效表征。我们展示了主要自旋缺陷的浓度增加了两倍，同时NV中心的[此处原文缺失相关内容]相对保持不变，这也为通过超精细相互作用抑制自旋翻转提供了一个潜在的实验证明。我们的工作为在混合电荷 - 自旋系统中研究具有时间和空间可调相互作用强度的多体动力学铺平了道路。
