TY - JOUR

T1 - Chiral Bloch states in single-layer graphene with Rashba spin-orbit coupling

T2 - Equilibrium spin current

AU - Avishai, Y.

AU - Band, Y. B.

N1 - Publisher Copyright:
© 2021 American Physical Society.

PY - 2021/8/15

Y1 - 2021/8/15

N2 - Focusing on equilibrium spin current density tensor, we analyze the spin physics of electrons in single layer graphene subject to a one-dimensional periodic Kronig-Penney potential u(x) and uniform Rashba spin-orbit coupling of strength λ. The combination of Dirac theory of massless two-dimensional electrons, Klein paradox, spin-orbit coupling, and the Bloch theorem yields peculiar features relevant to graphene spintronics. For transverse wave number ky=0, we show that: (1) The charge current and the spin density vector vanish. (2) Yet, the components Jxy,Jyx,Jzy of the equilibrium spin current density tensor are finite, oscillating in space, with amplitudes that increase quadratically for small λ and then linearly with λ. Quite remarkably, Jzy(x)≠0, that is, the spin is polarized along z, perpendicular to the graphene plane. (3) Due to the continuity equation, the space dependence of the spin current density Jyx(x) is associated with a finite spin torque density Ty(x)=∂Jyx(x)∂x.

AB - Focusing on equilibrium spin current density tensor, we analyze the spin physics of electrons in single layer graphene subject to a one-dimensional periodic Kronig-Penney potential u(x) and uniform Rashba spin-orbit coupling of strength λ. The combination of Dirac theory of massless two-dimensional electrons, Klein paradox, spin-orbit coupling, and the Bloch theorem yields peculiar features relevant to graphene spintronics. For transverse wave number ky=0, we show that: (1) The charge current and the spin density vector vanish. (2) Yet, the components Jxy,Jyx,Jzy of the equilibrium spin current density tensor are finite, oscillating in space, with amplitudes that increase quadratically for small λ and then linearly with λ. Quite remarkably, Jzy(x)≠0, that is, the spin is polarized along z, perpendicular to the graphene plane. (3) Due to the continuity equation, the space dependence of the spin current density Jyx(x) is associated with a finite spin torque density Ty(x)=∂Jyx(x)∂x.

UR - http://www.scopus.com/inward/record.url?scp=85113191026&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.104.075414

DO - 10.1103/PhysRevB.104.075414

M3 - Article

AN - SCOPUS:85113191026

VL - 104

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 7

M1 - 075414

ER -