| Title: |
The Sign of Three: Spin/Charge Density Waves at the Boundaries of Transition Metal Dichalcogenides |
| Authors: |
Krishnamurthi, Sridevi, Brocks, Geert |
| Source: |
Phys. Rev. B 102, 161106 (2020) |
| Publication Year: |
2020 |
| Collection: |
Condensed Matter |
| Subject Terms: |
Condensed Matter - Materials Science |
| More Details: |
One-dimensional grain boundaries of two-dimensional semiconducting {\MX} (M= Mo,W; X=S,Se) transition metal di-chalcogenides are typically metallic at room temperature. The metallicity has its origin in the lattice polarization, which for these lattices with $D_{3h}$ symmetry is a topological invariant, and leads to one-dimenional boundary states inside the band gap. For boundaries perpendicular to the polarization direction, these states are necessarily 1/3 occupied by electrons or holes, making them susceptible to a metal-insulator transition that triples the translation period. Using density-functional-theory calculations we demonstrate the emergence of combined one-dimensional spin density/charge density waves of that period at the boundary, opening up a small band gap of $\sim 0.1$ eV. This unique electronic structure allows for soliton excitations at the boundary that carry a fractional charge of $\pm 1/3\ e$. |
| Document Type: |
Working Paper |
| DOI: |
10.1103/PhysRevB.102.161106 |
| Access URL: |
http://arxiv.org/abs/2005.02519 |
| Accession Number: |
edsarx.2005.02519 |
| Database: |
arXiv |
