Designing atomic-scale transistor in topological insulators through vacancy-induced localized modes

Topological insulators (TIs) have been considered as promising candidates for next generation of electronic devices due to their topologically protected quantum transport phenomena. In this work, a scheme for atomic-scale field effect transistor based on vacancy-induced edge states in TIs is promoted. By designing the positions of vacancies, the closed channel between source and drain terminals provided by vacancy-induced edge states can have the energy spectra with a gap between edge and bulk states. When gate terminal receive the signal, electric field applied by gate terminal can shift quasi Fermi energy of the closed channel from edge states into the gap, and hence open the channel between source and drain terminals. The energy spectra and the effect of electric field are demonstrated using Haldane model and density functional theory respectively. This work suggest possible applicational potentials of vacancy-induced edge states in TIs for atomic-scale electronics.