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arXiv 2602.02174cond-mat.supr-con
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对比双层和三层镍酸盐中动量选择性的自旋密度波间隙

Contrasting Momentum-Selective Spin-Density-Wave Gaps in Bilayer and Trilayer Nickelates

Beijing Institute of Technology(北京理工大学);Wuhan University of Science and Technology(武汉科技大学);Hefei National Laboratory(合肥国家实验室);New Cornerstone Science Laboratory(新基石科学实验室);Beijing National Laboratory for Condensed Matter Physics(北京凝聚态物理国家实验室);University of Chinese Academy of Sciences(中国科学院大学);Songshan Lake Materials Laboratory(松山湖材料实验室);State Key Laboratory of Surface Physics(表面物理国家重点实验室);Fudan University(复旦大学)

Jun Shu, Jun Shen, Xiaoxiang Zhou, Yinghao Zhu, Qingsong Wang, Dengjing Wang, Weihong He, Jie Yuan, Kui Jin, Dawei Shen, Congcong Le, Jun Zhao, Zengyi Du, Ge He, Donglai Feng

AI总结:

研究揭示了双层和三层镍酸盐中自旋密度波间隙的动量选择性差异,发现三重层中能隙在α和部分β口袋开放,而双层中仅在β口袋开放,为超导机制提供了新约束。

摘要:

确定密度波间隙在动量空间中何处打开对于识别层状镍酸盐中微观不稳定性的起源至关重要。利用极化分辨的电子拉曼散射,我们映射了三重层La4Ni3O10中自旋密度波(SDW)间隙的动量选择性。我们观察到在布里渊区中心的α口袋和接近区边界的一个β口袋部分上,谱权重发生SDW诱导的再分布,其特征是约55 meV的能隙。相比之下,在β口袋对角区域没有观察到类似的谱权重抑制,表明几乎没有或没有能隙打开。这种能隙拓扑结构与La3Ni2O7中的各向异性SDW间隙明显不同,后者仅在β口袋上打开。我们的结果确立了双层和三层镍酸盐之间不同的动量空间能隙拓扑结构,对相关超导性的有序波矢和密度波不稳定性机制提出了新的约束。

英文摘要:

Resolving where the density-wave gap opens in momentum space is essential for identifying the microscopic origin of the instability in layered nickelates. Using polarization-resolved electronic Raman scattering, we map the momentum selectivity of the spin-density-wave (SDW) gap in trilayer La4Ni3O10. We observe a SDW-induced redistribution of spectral weight on both the $α$ pocket at the Brillouin-zone centre and a portion of the $β$ pocket near the zone boundary, characterized by gap energies of approximately 55~meV. In contrast, no comparable spectral weight suppression is observed along the diagonal region of $β$ pockets, implying little or no gap opening. This gap topology contrasts sharply with that in La3Ni2O7, where anisotropic SDW gaps open solely on the $β$ pocket. Our results establish a distinct momentum-space gap topology between bilayer and trilayer nickelates, placing new constraints on the ordering wave vector and the mechanism of the density-wave instability relevant to superconductivity.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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