高圧力によって層状物質のイジング超伝導を実現(Pressure Unlocks Ising Superconductivity in Layered Material)

2026-10-20 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高磁場科学研究チームは、山東大学、安徽大学と共同で、有機分子の層間挿入と高圧印加を組み合わせ、層状物質1T-TaS₂(硫化タンタル)における特異な超伝導状態を明らかにした。研究では、有機分子を結晶の層間に挿入して層間相互作用を弱めた試料を作製し、通常の1T-TaS₂と高圧下での電子状態や超伝導の発現過程を比較した。その結果、通常試料では電荷密度波状態の抑制後に超伝導が出現したのに対し、有機分子を挿入した試料では、別の電子状態が抑制された後、より高い圧力下で超伝導が発現した。さらに、挿入試料の超伝導状態はイジング型の特徴を示し、面内の上部臨界磁場が従来のパウリ限界の2倍を超えるなど、磁場に対して高い耐性を持つことが分かった。本成果は、低次元量子材料の電子状態を制御し、特異な超伝導相を探索する新たな手法を提示するものである。研究成果は学術誌 Reports on Progress in Physics に掲載された。

高圧力によって層状物質のイジング超伝導を実現(Pressure Unlocks Ising Superconductivity in Layered Material)
Schematic illustration of organic intercalation in 1T-TaS2 and its high-pressure phase diagram. (Image by Chen Jiaqi)

<関連情報>

有機物層間挿入型1T -TaS2における圧力誘起イジング超伝導 Pressure-induced Ising superconductivity in organic-intercalated 1T-TaS2

Jiaqi Chen, Shuyang Wang, Lixuan Yu, Xuliang Chen, Chao An, Yonghui Zhou, Yilin Wang and Zhaorong Yang
Reports on Progress in Physics  Published: 21 September 2026
DOI:10.1088/1361-6633/aea4f0

Abstract

Layered transition metal dichalcogenides host a rich landscape of correlated electronic phases that are profoundly sensitive to interlayer coupling. Although both thinning and pressure have been individually used to tune these properties, the high-pressure behavior of low-dimensional systems remains largely unexplored. Here, we propose a synergistic tuning strategy by combination of organic cation intercalation and pressure to simulate the properties of low-dimensional materials under pressure. We show that intercalating cetyltrimethylammonium cations into the bulk 1T-TaS2 significantly weakens the interlayer coupling and leads to an effective reduction in dimensionality. Moreover, the intercalated sample exhibits distinct features under high pressure as compared with non-intercalated one. The superconductivity in the intercalated sample is induced accompanied by a complete suppression of nearly commensurate charge density wave order, differing from the melting of commensurate state in the non-intercalated case. Upon further compression up to 58.1 GPa, the superconductivity displays a dome-shaped evolution, also without showing re-enhancement that presented in the non-intercalated sample. More strikingly, the superconductivity in the intercalated 1T-TaS2 displays signatures of Ising superconductivity, with its in-plane upper critical field exceeding twice the Pauli paramagnetic limit. Our findings not only provide a powerful route for tuning the collective electronic states but also open up possibilities in searching for emergent phenomena in low-dimensional materials.

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