2026/08/05 by Duy Nguyen, Hari Paudyal, Joseph R. Sink +2
Physics and Astronomy · #cond-mat.mes-hall
7 pages, 5 figures
arxiv created 2026/08/05 · arxiv updated 2026/08/06
We report a combined scanning tunneling microscopy and atomistic theoretical study of Fe adatoms on the Bi2Te3(111) surface. Topographic imaging at 4.5~K shows that Fe adatoms in fcc and hcp hollow sites exhibit a threefold-symmetric contrast, consistent with the C3v symmetry of the adsorption site. However, simultaneously acquired differential conductance (dI/dV) maps reveal a pronounced reduction in symmetry, evidenced by differential contrast observed at nearest-neighbor Te sites. Density functional theory calculations show that the Fe/Bi2Te3 system undergoes a static Jahn--Teller distortion, reducing the adsorption symmetry from C3v to C1v, with the distorted configuration favored by 72.5~meV. Orbital-projected density of states calculations show that the occupied states near the Fermi level are dominated by dxz and dyz orbitals, whereas the unoccupied states are primarily of dz2, dx2-y2, and dxy character. The local density of states from these orbitals is in good qualitative agreement with experimental dI/dV spectra. Furthermore, simulated local-density-of-states maps using a tight-binding Green's function approach are consistent with experimental dI/dV maps, confirming that the reduced symmetry originates from the C1v structural distortion.