Complex Landau levels and related transport properties in the strained zigzag graphene nanoribbons

Abstract

The real magnetic fields (MFs) acting on the graphene can induce flat real Landau levels (LLs). As an analogy, strains in graphene can produce significant pseudo MFs, triggering the appearance of dispersive pseudo LLs. By analysing the low energy effective Hamiltonian, we introduce the concept of the effective orbital MFs to integrate the real MFs and pseudo MFs. Accordingly, we obtain the complex LLs which incorporate the real LLs and pseudo LLs, and calculate the related transport properties. With the aid of these ideas, we reveal the mechanism underlying the fragility of the pseudo LLs against disorders, and predict that the \(K\) and \(K'\) valleys have different robust performances against the Anderson disorders and dephasing effects. Furthermore, the tunability of the polarized valley currents is also studied, opening up new possibilities for the design of valleytronics devices.