近日，美国加州大学的N. Y. Yao及其研究团队取得一项新进展。经过不懈努力，他们利用量子传感器成像氢化物超导体中的迈斯纳效应。相关研究成果已于2024年2月28日在国际权威学术期刊《自然》上发表。

该研究团队成功展示了在兆巴压力下，利用亚微米空间分辨率在金刚石压砧内部进行局部磁力测定的能力。他们精心选择了一种与氮空穴色心固有对称性相匹配的晶体切割方式，确保了在极端压力下技术的有效性。为了进一步验证这一方法，研究人员将其应用于最近发现的氢化物超导体CeH₉的表征。通过同步进行磁力和电输运测量，他们观察到了超导的双重特征：迈斯纳效应的抗磁性特征和电阻急剧下降到接近零。

此外，研究人员还利用局部映射抗磁响应和磁捕获技术，成功成像了超导区域的几何形状，并在微米尺度上揭示了明显的不均匀性。这项研究工作将量子传感带到兆巴前沿，实现了超氢化物材料合成的闭环优化。

据悉，压力作为一种能够直接改变微观相互作用的强大手段，为探索凝聚相和地球物理现象提供了重要的调节方式。兆巴范围作为这一领域的前沿，近年来取得了诸多有趣的发现，包括高温超导体以及结构和化学价相变等。然而，在这一极端高压环境下，许多传统的测量技术都失效了。

附：英文原文

Title: Imaging the Meissner effect in hydride superconductors using quantum sensors

Author: Bhattacharyya, P., Chen, W., Huang, X., Chatterjee, S., Huang, B., Kobrin, B., Lyu, Y., Smart, T. J., Block, M., Wang, E., Wang, Z., Wu, W., Hsieh, S., Ma, H., Mandyam, S., Chen, B., Davis, E., Geballe, Z. M., Zu, C., Struzhkin, V., Jeanloz, R., Moore, J. E., Cui, T., Galli, G., Halperin, B. I., Laumann, C. R., Yao, N. Y.

Issue&Volume: 2024-02-28

Abstract: By directly altering microscopic interactions, pressure provides a powerful tuning knob for the exploration of condensed phases and geophysical phenomena. The megabar regime represents an interesting frontier, in which recent discoveries include high-temperature superconductors, as well as structural and valence phase transitions. However, at such high pressures, many conventional measurement techniques fail. Here we demonstrate the ability to perform local magnetometry inside a diamond anvil cell with sub-micron spatial resolution at megabar pressures. Our approach uses a shallow layer of nitrogen-vacancy colour centres implanted directly within the anvil; crucially, we choose a crystal cut compatible with the intrinsic symmetries of the nitrogen-vacancy centre to enable functionality at megabar pressures. We apply our technique to characterize a recently discovered hydride superconductor, CeH₉. By performing simultaneous magnetometry and electrical transport measurements, we observe the dual signatures of superconductivity: diamagnetism characteristic of the Meissner effect and a sharp drop of the resistance to near zero. By locally mapping both the diamagnetic response and flux trapping, we directly image the geometry of superconducting regions, showing marked inhomogeneities at the micron scale. Our work brings quantum sensing to the megabar frontier and enables the closed-loop optimization of superhydride materials synthesis.

DOI: 10.1038/s41586-024-07026-7

Source: https://www.nature.com/articles/s41586-024-07026-7