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 Co1/3NbS2, 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 a1g 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.

Crystallographic chirality can mediate various optical and electrical magnetochiral effects. Since these effects have been studied in bulk optical, transport or non-local probe setups, investigation with a local probe is necessarily the next step towards further understanding of the intriguing phenomena closer to the quantum regime. We observed a spin-polarized scanning tunneling microscopy (SP-STM) contrast in the chiral domains of Co1/3NbS2 in a paramagnetic state, which is unexpected in the conventional SP-STM mechanism. This spin-polarized tunneling, depending on the local structural chirality, is argued to be an inverse magnetochiral effect due to a dynamic coupling between tunneling electrons and chirality. In addition, using the standard STM, we also find magnetochiral nonreciprocal tunneling in the presence of external magnetic fields, considered as the inverse process. Our results demonstrate a new application of SP-STM in detecting the dynamic interaction of tunneling electrons with broken crystallographic symmetries.

Crystals of Lu1‐xScxBO3:Ce (x = 0.2, 0.5, 0.7) are prepared by the Czochralski method and characterized by single crystal XRD, Raman spectroscopy, and vacuum UV excitation spectroscopy.

Intercalation raises manifold possibilities to manipulate the properties of two-dimensional (2D) materials1, and its impact on local electronic/magnetic properties has drawn much attention with the rise of nano-structured 2D materials2,3. Typically, changing an ionic state in a solid involves a dramatic local change of energy as well as orbital/spin magnetic moment from its ground state. However, the atomic investigation of the charging process of an intercalant ion in 2D material has never been explored while such subject has been studied in artificially deposited atoms on thin insulating 2D layers using scanning probe microscopy4–7. Herein, we demonstrate an atomical manipulation of the charge and spin state of Co ions on a metallic NbS2, obtained by cleaving of Co-intercalated NbS2. Density functional theory investigation of various Co configurations reveals that the charging is possible due to a change in the crystal field at the surface and a significant coupling between NbS2 and intercalants occurs via orbitals of the a1g symmetry. The results can be generalized to numerous other combinations of intercalants and base matrixes, suggesting that intercalated transition metal dichalcogenides can be a new platform to introduce single-atom operation 2D electronics/spintronics.