Brangi Pietro Nicolò, Martini Francesca, Cudazzo Pierluigi, Calandra Matteo
Department of Physics, University of Trento, Via Sommarive 14, 38123 Povo, Italy.
J Phys Chem Lett. 2025 Jun 12;16(23):5739-5744. doi: 10.1021/acs.jpclett.5c01013. Epub 2025 Jun 2.
Graphitic carbon nitride (g-CN) hosts lone pairs arising from broken carbon-nitrogen bonds in its heptazine structure. These strongly localized and weakly hybridized states form ultraflat bands, potentially leading to correlated states when doped. Using first-principles calculations, we show that field-effect hole doping in single-layer g-CN depletes these lone pairs, unveiling a rich phase diagram with a complex interplay of superconducting, half-metallic, and insulating ferromagnetic phases, even at very low charging and in the absence of transition metal ions. Our work highlights gated two-dimensional systems hosting lone pairs as a novel platform for strongly correlated states.
石墨相氮化碳（g-CN）在其七嗪结构中存在因碳氮键断裂而产生的孤对电子。这些高度局域化且弱杂化的态形成了超平带，掺杂时可能导致关联态。通过第一性原理计算，我们表明单层g-CN中的场效应空穴掺杂会耗尽这些孤对电子，揭示出一个丰富的相图，其中超导、半金属和绝缘铁磁相等复杂相互作用，即使在非常低的电荷状态且不存在过渡金属离子的情况下也是如此。我们的工作突出了拥有孤对电子的门控二维系统作为强关联态的新型平台。
