Tunable Flat Bands and magnetism in Triangulene-based Superatomic Graphene

Wenya Zhai; Tingfeng Zhang; Fengkun Chen; Xiuqin Lu; Yunlong Xia; Zengfu Ou; Ye Chen; Donghui Guo; Meifang Zhu; Zhengfei Wang; Jingcheng Li

arXiv · 2606.20321

Tunable Flat Bands and magnetism in Triangulene-based Superatomic Graphene

Wenya Zhai·Tingfeng Zhang·Fengkun Chen·Xiuqin Lu·Yunlong Xia·Zengfu Ou·Ye Chen·Donghui Guo·Meifang Zhu·Zhengfei Wang·Jingcheng Li

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Abstract

Superatomic graphene platforms host a rich portfolio of flat-band-driven exotic quantum properties, yet their experimental realization remains challenging. Here, we report the bottom-up on-surface synthesis of superatomic graphene using phosphorus-doped triangulene as building blocks. Scanning tunneling microscopy and spectroscopy measurements resolve the well-defined honeycomb lattice of as-fabricated superatomic graphene and demonstrate the characteristic Dirac band and flat band electronic structures. Density functional theory calculations reveal that the flat bands originate from the in-plane p$_x,_y$-like frontier orbitals of the phosphorus-doped triangulene units, leading to intrinsic half-metallic behavior. Furthermore, oxygen functionalization of the molecular precursor enables deterministic modulation of the electronic structure and magnetic ordering. This work establishes a general platform for designing correlated quantum materials with tunable flat band properties.

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Wenya Zhai, Tingfeng Zhang, Fengkun Chen, Xiuqin Lu, Yunlong Xia, Zengfu Ou, Ye Chen, Donghui Guo, Meifang Zhu, Zhengfei Wang, Jingcheng Li. 2026-06-18. Tunable Flat Bands and magnetism in Triangulene-based Superatomic Graphene. https://arxiv.org/abs/2606.20321

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