Stacking Order, Perfect Spin Polarization, and Giant Magnetoresistance in Zigzag Graphene/h-BN Heterobilayer Nanoribbons

In a van der Waals heterostructure of two-dimensional materials, electronic properties are tunable by means of stacking orders. Here, we study the spin-dependent quantum transport in the bilayer of ferromag-netic zigzag-edged graphene/hexagonal-BN nanoribbons (ZGr-BNNRs) using density-functional theory combined with the Keldysh nonequilibrium Green's-function method. We reveal a strong odd-even effect of transport across the ZGr-BNNRs and a giant magnetoresistance value observed only in even-width ZGr-BNNRs. More interestingly, this value can be optimized by engineering stacking orders, yielding the perfect spin polarization efficiency of 100% and the magnetoresistance value of over 104 in even -width ZGr-BNNRs. Our results provide a route to design and fabricate high-performance spin filters and magnetic storage devices.

Automated summary

In this study, the spin-dependent quantum transport in a van der Waals heterostructure of bilayer ferromagnetic zigzag-edged graphene/hexagonal-BN nanoribbons (ZGr-BNNRs) is investigated using density-functional theory combined with the Keldysh nonequilibrium Green's-function method. The results reveal a strong odd-even effect of transport across the ZGr-BNNRs, as well as a giant magnetoresistance value observed only in even-width ZGr-BNNRs. Interestingly, this value can be optimized by engineering stacking orders, leading to a perfect spin polarization efficiency of 100% and a magnetoresistance value of over 104 in even-width ZGr-BNNRs. These findings provide a pathway for the design and fabrication of high-performance spin filters and magnetic storage devices.