This week’s image is from a paper recently published in Journal of Physics: Condensed Matter: The influence of anisotropic Rashba spin–orbit coupling on current-induced spin polarization in graphene. This work by Mir Vahid Hosseini uses Green’s function method and linear response theory to calculate the magnitude and direction of spin polarization in a disordered graphene layer, when in the presence of anisotropic Rashba spin–orbit coupling. He shows that anisotropic Rashba spin–orbit coupling gives rise to the non-linear dependence of spin polarization at the range of energies within the Lifshitz points of the conduction and valence bands. This could provide new ways to control spin-polarized current.

Contour plot of constant energy lines of lowest conduction energy band. Here, λ₂ = 2λ₁ = 2. Figure adapted from J. Phys.: Condens. Matter 29 315502, © Copyright 2017 IOP Publishing.

The image above displays a contour plot of constant energy lines of the lowest conduction energy band in the disordered graphene layer. Band inversion due to anisotropic spin-orbit coupling leads to the changing of Fermi line topology from a closed curve to two disconnected closed curves, resulting in a Lifshitz transition.

Click here to read the Full Article.

This work is licensed under a Creative Commons Attribution 3.0 Unported License

Categories: Journal of Physics: Condensed Matter, JPhys+

Tags: anisotropy, band inversion, current, Graphene, Image of the week, lifshitz, rashba, Spin-orbit coupling, valence