Quantum transport properties of hybrid BN-C nanotubes: Strong spin filtering effect robust against Stone-Wales defects

We study the spin-polarized electron transport properties of hybrid BN-C nanotubes (BN-CNTs) in their pristine form and with Stone-Wales defects, namely, C-x(BN)(10-x), using combined first-principles density functional theory and quantum transport simulations. We show that the band structures of pristine BN-CNTs can be sensitively tuned by their composition, transiting from the nonmagnetic semiconductor to half-semimetal and finally to a narrow gap semiconductor with increasing x. The spin-dependent current-voltage characteristics are sensitively modulated by x in the hybridized C-x(BN)(10-x). The SW defect acts as an active scattering center for BN-CNTs, which decreases the overall conductance of nanotubes. Remarkably, a spin-filtering effect (SFE) with nearly 96% filtering efficiency is observed in C-4(BN)(6), and such a high SFE remains robust even in the presence of Stone-Wales defects. These results reveal the potential role of hybrid BN-CNT as a building block for spintronic device technology.