Rashba spin-orbit interaction in graphene and zigzag nanoribbons

Abstract

We investigate the effects of Rashba spin-orbit (RSO) interactions on the electronic band-structure and corresponding wavefunctions of graphene. By exactly solving a tight-binding model Hamiltonian we obtain the expected splitting of the bands -due to the SU(2) spin symmetry breaking-that is accompanied by the appearance of additional Dirac points. These points are originated by valenceconduction band crossings. By introducing a convenient gauge transformation we study a model for zigzag nanoribbons with RSO interactions. We show that RSO interactions lift the quasi-degeneracy of the edge band while introducing a state-dependent spin separation in real space. Calculation of the average magnetization perpendicular to the ribbon plane suggest that RSO could be used to produce spin-polarized currents. Comparisons with the intrinsic spin-orbit (I-SO) interaction proposed to exist in graphene are also presented.

Weak localization of bismuth cluster-decorated graphene and its spin–orbit interaction

“…The Bychkov-Rashba SOC requires the breaking of the mirror symmetry in the graphene plane, which can destroy the QSH state [31][32][33]. On the other hand, the intrinsic Kane-Mele SOC satisfies a full invariant of the transformations of the point group, which can favor the existence of the QSH state.…”

Rashba and intrinsic spin-orbit interactions in biased bilayer graphene

“…Later, it was found that the Rashba interaction has interesting effects on its own, leading to a splitting of the Dirac point into four identical points. 3 This splitting is missed in the low-energy calculations used in Refs. 1 and 2.…”

Nonlinear optical conductivity of bilayer graphene with Rashba spin-orbit interaction in the terahertz regime

“…According to Ref. 17, it is found that the intralayer Rashba coupling in an unbiased bilayer not only splits the K (K 0 ) point into four, in a different way than it does for monolayer graphene, 18 but also creates a Dirac cone out of a parabolic band. In addition, a Mexican-hat band arises at the K (K 0 ) point when the pure SOI interactions exist or the layers are solely biased.…”

“…One Dirac point is now split into four gapless points. [16][17][18][19][20] One of them remains at the K (K 0 ) point and other three link up an equilateral triangle around the K (K 0 ) point. The warping changes the topology of the low energy bands at the K (K 0 ) point of the graphene's BZ.…”