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arXiv · 2509.19075

Layer controlled orbital selective Mott transition in monolayer nickelate

Byungmin Sohn·Minjae Kim·Sangjae Lee·Wenzheng Wei·Juan Jiang·Fengmiao Li·Sergey Gorovikov·Marta Zonno·Tor Pedersen·Sergey Zhdanovich·Ying Liu·Huikai Cheng·Ke Zou·Yu He·Sohrab Ismail-Beigi·Frederick J. Walker·Charles H. Ahn
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Abstract

Dimensionality and electronic correlations are crucial elements of many quantum material properties. An example is the change of the electronic structure accompanied by the loss of quasiparticles when a metal is reduced from three dimensions to a lower dimension, where the Coulomb interaction between carriers becomes poorly screened. Here, using angle-resolved photoemission spectroscopy (ARPES), we report an orbital-selective decoherence of spectral density in the perovskite nickelate LaNiO3 towards the monolayer limit. The spectral weight of the dz2 band vanishes much faster than that of the dx2-y2 band as the thickness of the LaNiO3 layer is decreased to a single unit cell, indicating a stronger correlation effect for the former upon dimensional confinement. Dynamical mean-field theory (DMFT) calculations show an orbital-selective Mott transition largely due to the localization of dz2 electrons along the c axis in the monolayer limit. This orbital-selective correlation effect underpins many macroscopic properties of nickelates, such as metal-to-insulator transition and superconductivity, where most theories are built upon a dx2-y2-dz2 two-band model.

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Byungmin Sohn, Minjae Kim, Sangjae Lee, Wenzheng Wei, Juan Jiang, Fengmiao Li, Sergey Gorovikov, Marta Zonno, Tor Pedersen, Sergey Zhdanovich, Ying Liu, Huikai Cheng, Ke Zou, Yu He, Sohrab Ismail-Beigi, Frederick J. Walker, Charles H. Ahn. 2025-09-23. Layer controlled orbital selective Mott transition in monolayer nickelate. https://doi.org/10.1103/n92p-xrhl

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