Publication Date: 2025
Journal of Magnetism and Magnetic Materials (03048853)622
We investigate the physical properties of triangular and hexagonal Buckled-Bismuth quantum dots with zigzag and armchair boundary atoms passivated by hydrogen atoms. Also using the multi-orbital tight-binding model, the energy spectra of the aforementioned structures are studied. We obtained that, the H-passivation on the boundary atoms of considered quantum dots decreases the number of states within the energy gap value (edge states) compared to the number of edge modes of these structures without H-passivation. So, some states are saturated by H atoms and removed from the energy gap interval in the H-passivation quantum dots. These removed states are known as dangling bonds. We also obtained that the number of edge states in armchair triangular Bismuth quantum dot is more than other ones. By computing the probability density of states, we understand that edge atoms form the mentioned edge states. Also, we study the energy spectra of the above H-passivated quantum dots under the perpendicular magnetic fields. We obtained that, by turning on and off the spin–orbit-coupling interaction, the removed edge states (saturated by H atoms) are trivial modes and remained edge states are non-trivial ones (protected symmetry). Therefore, H-passivated quantum dots can be applied to measure the fluctuation in the conductance of their edge states. Also in the presence of magnetic field, we see Landau levels. Finally we find that, for forming these Landau levels, the edge atoms are more important than bulk atoms. © 2025
