Tunable Single-Atomic Charges on a Cleaved Intercalated Transition Metal Dichalcogenide

Seongjoon Lim; Shangke Pan; Kefeng Wang; Alexey V Ushakov; Ekaterina V Sukhanova; Zakhar I Popov; Dmitry G Kvashnin; Sergey V Streltsov; Sang-Wook Cheong

doi:10.1021/acs.nanolett.1c03706

Tunable Single-Atomic Charges on a Cleaved Intercalated Transition Metal Dichalcogenide

Nano Lett. 2022 Feb 23;22(4):1812-1817. doi: 10.1021/acs.nanolett.1c03706. Epub 2021 Dec 10.

Authors

Seongjoon Lim¹, Shangke Pan^{1

2}, Kefeng Wang¹, Alexey V Ushakov³, Ekaterina V Sukhanova⁴, Zakhar I Popov^{4

5}, Dmitry G Kvashnin^{4

6}, Sergey V Streltsov^{3

7}, Sang-Wook Cheong¹

Affiliations

¹ Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers The State University of New Jersey, Piscataway, New Jersey 08854, United States.
² State Key Laboratory Base of Novel Function Materials and Preparation Science, School of Material Sciences and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, China.
³ Institute of Metal Physics, S. Kovalevskaya Street 18, Yekaterinburg 620108, Russia.
⁴ Emanuel Institute of Biochemical Physics of RAS, 4 Kosygin Street, 119334, Moscow, Russia.
⁵ Plekhanov Russian University of Economics, 36 Stremyanny per., 117997, Moscow, Russia.
⁶ Moscow Institute of Physics and Technology (State University), 9 Institutskiy per., 141701, Dolgoprudny, Moscow Region, Russia.
⁷ Department of Theoretical Physics and Applied Mathematics, Ural Federal University, Mira Street 19, Yekaterinburg 620002, Russia.

PMID: 34890208
DOI: 10.1021/acs.nanolett.1c03706

Abstract

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 Co_1/3NbS₂, 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 NbS₂ and Co via a_1g 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.

Keywords: intercalation; metastable charge state; scanning tunneling microscopy (STM); transition metal dichalcogenide.