Lim Seongjoon, Pan Shangke, Wang Kefeng, Ushakov Alexey V, Sukhanova Ekaterina V, Popov Zakhar I, Kvashnin Dmitry G, Streltsov Sergey V, Cheong Sang-Wook
Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers The State University of New Jersey, Piscataway, New Jersey 08854, United States.
State Key Laboratory Base of Novel Function Materials and Preparation Science, School of Material Sciences and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, China.
Nano Lett. 2022 Feb 23;22(4):1812-1817. doi: 10.1021/acs.nanolett.1c03706. Epub 2021 Dec 10.
Control of a single ionic charge state by altering the number of bound electrons has been considered as an ultimate testbed for atomic charge-induced interactions and manipulations, and such subject has been studied in artificially deposited objects on thin insulating layers. We demonstrate that an entire layer of controllable atomic charges on a periodic lattice can be obtained by cleaving metallic CoNbS, an intercalated transition metal dichalcogenide. We identified a metastable charge state of Co with a different valence and manipulated atomic charges to form a linear chain of the metastable charge state. Density functional theory investigation reveals that the charge state is stable due to a modified crystal field at the surface despite the coupling between NbS and Co via a orbitals. The idea can be generalized to other combinations of intercalants and base matrices, suggesting that they can be a new platform to explore single-atom-operational 2D electronics/spintronics.
通过改变束缚电子的数量来控制单一离子电荷态，已被视为原子电荷诱导相互作用和操纵的终极试验平台，并且此类课题已在薄绝缘层上的人工沉积物体中得到研究。我们证明，通过劈开金属CoNbS（一种插层过渡金属二硫属化物），可以在周期性晶格上获得可控原子电荷的完整层。我们识别出具有不同价态的Co的亚稳电荷态，并操纵原子电荷以形成亚稳电荷态的线性链。密度泛函理论研究表明，尽管NbS和Co通过轨道耦合，但由于表面晶体场的改变，电荷态是稳定的。这一想法可以推广到插层剂和基体的其他组合，表明它们可以成为探索单原子操作二维电子学/自旋电子学的新平台。
