二次元超伝導体におけるマイスナー効果の観測(Researchers Observe Meissner Effect in Two-Dimensional Superconductors)

2026-04-28 合肥物質科学研究院(HFIPS)

中国科学院合肥物質科学研究院の研究チームは、南京大学・燕山大学と共同で、二次元超伝導体におけるマイスナー効果を高感度磁気測定技術により初めて直接観測した。従来は微小体積ゆえ磁気信号が極めて弱く、ゼロ抵抗測定に依存していたが、本研究ではカンチレバー磁力計を基盤とした手法と理論を構築し、磁化や磁化率を高精度で抽出。検出感度は既存法を大幅に上回った。層状二硫化タングステン(2M-WS2)を用い、ナノスケール試料でヒステリシスを確認し、極薄試料でも反磁性遮蔽を測定、二次元系でのマイスナー効果の実証に成功した。低次元超伝導の磁気特性解明に道を開く成果である。

二次元超伝導体におけるマイスナー効果の観測(Researchers Observe Meissner Effect in Two-Dimensional Superconductors)
Ultrasensitive detection of the Meissner effect in two-dimensional superconductors (Image by WANG Kang)

<関連情報>

微小スケール二次元ファンデルワールス超伝導体におけるマイスナー効果の解明 Probing the Meissner Effect in Microscale Two-Dimensional van der Waals Superconductors

Kang Wang, Meng Shi, Qikang Gan, Feixiang Diao, Ning Wang, Xueqin Li, Ran Wang, Teng Xu, Yizhou Liu, Lin Hao, Ning Hao, Tianyu Xue, Lei Wang, Haifeng Du
Advanced Materials  Published: 16 April 2026
DOI:https://doi.org/10.1002/adma.73127

ABSTRACT

(2D) van der Waals (vdW) superconductors provide a platform for investigating unconventional superconductivity, topological states, and low-power quantum devices. However, due to their extremely small volume and weak magnetic signals, their superconductivity has primarily been assessed through zero resistance, while the Meissner effect remains largely unexplored. Here, we demonstrate that dynamic cantilever magnetometry (DCM) can be used to probe the intrinsic Meissner diamagnetism in 2D vdW superconductors. A theoretical model is first established to quantitatively extract magnetization and susceptibility. Building on this, using 2M-WS2 as a model system, a clear magnetization hysteresis loop characteristic of type-II superconductivity is resolved. Meanwhile, susceptibility is also detected down to a thickness of 5.7 nm, revealing a screening efficiency of about 89.9% at 4.6 mT, indicative of nearly complete diamagnetic screening. We analyze that DCM achieves a magnetization sensitivity of ~1.1×10-17 A・m2 and susceptibility sensitivity of ~9.4×10-17 A・m2 /T. Our results provide crucial magnetic signatures of the Meissner effect in 2D vdW superconductors and highlight the capability of DCM for magnetic validation of superconductivity in low-dimensional materials.

1701物理及び化学
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