标题：Dichotomy between frustrated local spins and conjugated electrons in a two-dimensional metal-organic framework
作者：Jiang, Wei; Liu, Zheng; Mei, Jia-Wei; Cui, Bin; Liu, Feng
作者机构：[Jiang, Wei; Liu, Feng] Univ Utah, Dept Mat Sci & Engn, Salt Lake City, UT 84112 USA.; [Jiang, Wei] Univ Minnesota, Dept Elect & Comp Engn, Minneapo 更多
通讯作者：Liu, Zheng;Liu, F;Liu, Z;Mei, JW;Mei, JW
通讯作者地址：[Liu, F]Univ Utah, Dept Mat Sci & Engn, Salt Lake City, UT 84112 USA;[Liu, Z]Tsinghua Univ, Inst Adv Study, Beijing 100084, Peoples R China;[Mei, JW]S 更多
摘要：Dichotomy between local spins and conjugated electrons spawns various exotic physical phenomena, however, it has mostly been reported in three-dimensional (3D) inorganic systems. We show, for the first time, that a rare 2D metal-organic framework exhibits intriguing dichotomy behavior, which can be directly identified through scanning tunneling microscopy/spectroscopy (STM/STS). In a newly synthesized Cu-hexaiminobenzene [Cu-3(HAB)(2)], on the one hand, the Cu2+ ions form an ideal S - 1/2 antiferromagnetic (AFM) kagome lattice; on the other hand, the conjugated-electrons from the organic ligands produce a frustrated (x,y) model on a honeycomb lattice, giving rise to completely dispersionless energy bands around the Fermi level that favour the ferromagnetic (FM) state. Remarkably, the frustrated local spins and conjugated electrons interact through a strong FM Hund's coupling, giving rise to a wide range of intriguing quantum phases. Furthermore, we propose that this dichotomy can be directly characterized through STM/STS measurements due to its special 2D nature, which provides a unique exciting platform to investigate the dichotomy of frustrated spins and electrons in a single lattice.