Applied scanning transmission electron microscopy (STEM) to a 2D Ta-Te quasi crystal and its approximant, and combined it with theoretical calculations.
Significance and Impact
Dramatic real-space imaging shows directly atomic positions within the 2D sheets, and theory shows emergence of topological phase tunable by layer number.
- Cleaved atomically thin sheets of 2D quasicrystal Ta1.6Te derived from a layered transition metal dichalcogenide
- Used STEM imaging and electron diffraction to determine atomic positions
- Density functional theory (DFT) reveals presence of symmetry-protected nodal crossings in the quasicrystalline and approximant phases, tunable by layer number