The interplay among orbital-selective Mott physics, Hund's coupling, tunable structural motifs, and Kondo-like scattering establishes a compelling paradigm for understanding and engineering correlated multi-orbital systems, as vividly exemplified by nickelate superconductors. Here, using high-resolution angle-resolved photoemission spectroscopy combined with theoretical calculations, we systematically investigate the electronic properties of trilayer nickelates. In La4Ni3O10, we observe pronounced interorbital hybridization, whereas in Pr4Ni3O10, the flat d_(z^2 ) band becomes markedly incoherent and diminishes in spectral weight. By contrast, the dispersive d_(x^2-y^2 ) bands retain coherence in both compounds. This striking incoherence/coherence dichotomy identifies an orbital-selective Mott phase modulated by the interlayer Ni-O-Ni bonding angle. The depletion of the d_(z^2 ) orbitals further frustrates the interorbital hybridization and influences the density-wave transition in Pr4Ni3O10. Moreover, the density-wave gap is substantially reduced in Pr4Ni3O10, likely due to extra scattering channels provided by the local moments of Pr3+ cations. Our findings elucidate the intricate interplay among lattice, orbital, spin, and electronic degrees of freedom and reveal a feasible structural control parameter for the multi-orbital correlated state in trilayer nickelates, which provide a concrete framework for understanding the emergence of superconductivity under high pressure.
@article{arxiv.2602.03658,
title = {Orbital-selective Mottness Driven by Geometric Frustration of Interorbital Hybridization in Pr4Ni3O10},
author = {Yidian Li and Mingxin Zhang and Xian Du and Cuiying Pei and Jieyi Liu and Houke Chen and Wenxuan Zhao and Kaiyi Zhai and Yinqi Hu and Senyao Zhang and Jiawei Shao and Mingxin Mao and Yantao Cao and Jinkui Zhao and Zhengtai Li and Dawei Shen and Yaobo Huang and Makoto Hashimoto and Donghui Lu and Zhongkai Liu and Yulin Chen and Hanjie Guo and Yilin Wang and Yanpeng Qi and Lexian Yang},
journal= {arXiv preprint arXiv:2602.03658},
year = {2026}
}