镍酸盐超晶格中层和轨道选择性莫特物理驱动的维度交叉
Layer- and Orbital-Selective Mott Physics Driving Dimensional Crossover in Nickelate Superlattices
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中文总结 AI 辅助
本研究提出镍酸盐异质结构平台，通过层和轨道选择性莫特转变驱动维度交叉，为非常规超导和莫特晶体管设计提供新途径。
中文摘要 AI 辅助
量子材料的设计以操控维度和电子关联是探索涌现现象的核心焦点。我们提出了一种新的关联量子材料平台，通过将双层和单层LaNiO$_3$与单层LaAlO$_3$间隔层结合，并在LaAlO$_3$衬底的压缩应变下，在镍酸盐异质结构中实现层和轨道选择性莫特转变（LOSMT）。LOSMT源于顶角Ni($d$)-$z^2$轨道的层依赖维度限制以及应变诱导的轨道简并解除。单层LaNiO$_3$表现出轨道选择性莫特绝缘相，在Ni($d$)-$z^2$轨道中存在莫特间隙，而双层LaNiO$_3$表现出多轨道金属相，通过冷却时Ni($d$)-$z^2$轨道的层间杂化触发轨道选择性莫特转变。在密度泛函理论加动力学平均场理论（DFT+DMFT）框架内的计算表明，LOSMT通过局域顶角Ni($d$)-$z^2$轨道的金属化实现面外电子输运，从而驱动维度交叉，而平面Ni($d$)-$x^2-y^2$轨道在整个转变过程中保持巡游性。LOSMT的出现为工程化关联量子材料以探索非常规超导性和莫特晶体管功能提供了新途径。
英文摘要
The design of quantum materials to manipulate dimensionality and electronic correlations is a central focus in the exploration of emergent phenomena. We propose a new correlated quantum material platform for realizing a layer- and orbital-selective Mott transition (LOSMT) in a nickelate heterostructure by combining bilayer and monolayer LaNiO$_3$ separated by a monolayer LaAlO$_3$ spacer under compressive strain from the LaAlO$_3$ substrate. The LOSMT emerges from the layer-dependent dimensional confinement of the apical Ni($d$)-$z^2$ orbital and strain-induced lifting of the orbital degeneracy. The monolayer LaNiO$_3$ exhibits an orbital-selective Mott insulating phase with a Mott gap in the Ni($d$)-$z^2$ orbital, whereas the bilayer LaNiO$_3$ exhibits a multi-orbital metallic phase, triggering the orbital-selective Mott transition upon cooling $via$ inter-layer hybridization of the Ni($d$)-$z^2$ orbitals. Calculations within the density functional theory plus dynamical mean-field theory (DFT+DMFT) framework reveal that the LOSMT drives a dimensional crossover by enabling out-of-plane electronic transport through the metallization of the localized apical Ni($d$)-$z^2$ orbital, while the planar Ni($d$)-$x^2-y^2$ orbital remains itinerant across the transition. The emergence of the LOSMT provides a new pathway for engineering correlated quantum materials toward unconventional superconductivity and Mott-transistor functionalities.
发表机构
- Jeonbuk National University（全北国立大学）
- Sungkyunkwan University（成均馆大学）
- Yale University（耶鲁大学）
机构由 AI 辅助整理，请以论文原文为准。
