A recent experiment reported the presence of robust zero-energy states with peculiar properties in a trilayer heterostructure $\mathrm{MnTe}/{\mathrm{Bi}}_2{\mathrm{Te}}_3/\mathrm{Fe}(\mathrm{Te},\mathrm{Se})$. In this study, we provide a comprehensive understanding of the magnetic and electronic properties of this heterostructure. We propose that magnetic Mn-Bi antisite defects are formed in the topmost sublayer of ${\mathrm{Bi}}_2{\mathrm{Te}}_3$ and remain hidden beneath the MnTe layer. Moreover, we reveal that these defects can give rise to two types of quasiparticles. First, the defect itself generates a Yu-Shiba-Rusinov state, and second, a pair of Majorana zero modes emerge from the superconducting phase domain wall induced by the defect. These two types of quasiparticles exhibit contrasting responses to magnetic fields, temperature, and other factors. The coexistence and mutual cooperation of both types of quasiparticles can account for the experimental observations. Furthermore, we propose a simpler heterostructure that possesses advantages in generating and finely modulating Majorana zero modes.

Close

PrevNext

View figure in article

• Topological superconductors
• Heterostructures
• Band structure methods
• Density functional theory