Spin-momentum Locking in an Array of Defect Lines in Gated Bilayer Graphene

Graphene can have defect lines with pentagons and octagons (8-55) that induce localized states [1]. This domain wall in gated bilayer graphene produces a change between AB to BA stacking and presents topological states in the gap [2-4]. In this work using density functional theory calculations, we investigate an array of these defect lines in bilayer graphene. We found that the band structure shows a magnetic phase in which the spin is locked to the momentum, as in topological insulators. We also follow the topological states that appear even without a gate because of the array of defect lines. We lastly study the differences in spin bands and identified topological states when engineering by doping and/or electric field. All these results are summing to the new interesting data of the correlated behavior of electrons with the stacking in two-dimensional materials [5].

[1] Pelc, M., Chico, L., Ayuela, A., & Jaskólski, W. Phys Rev B, 87(16), 165427 (2013).
[2] Pelc, M., Jaskólski, W., Ayuela, A., & Chico, L. Phys Rev B, 92(8), 085433 (2015).
[3] Jaskólski, W., Pelc, M., Chico, L., & Ayuela, A. Nanoscale, 8(11), 6079-6084 (2016).
[4] Jaskólski, W., Pelc, M., Bryant, G. W., Chico, L., & Ayuela, A. 2D Materials, 5(2), 025006 (2018).
[5] Cao, Y. et al Nature, 556(7699), 43(2018).