Modulating the resonance transport of edge states in topological insulator junction

Abstract

This work investigates how the width (Ny) of zigzag silicene-like nanoribbons, along with defect size and position, affect the resonance transmission of a topological insulator junction with anisotropic chiral and helical edge states. Despite changes in the resonance peak with Ny below the critical value, neither a proportional nor inverse formula can adequately express the relationship between the resonance period (T) and Ny. The energy band calculations indicate that the change mechanism is attributed to the size effect on the band structure. We also examine the influence of the defect size and position on resonance and provide a detailed explanation by calculating the local bond current. It is found that specific defect size and position greatly impact the resonance peak, indicating the potential of modulating resonance using these two variables. These findings provide theoretical insights for controlling resonance.