Spin polarization dependence of quasiparticle properties in graphene

Abstract

We address spin polarization dependence of graphene's Fermi liquid properties quantitatively using a microscopic Random Phase Approximation theory in an interacting spin-polarized Dirac electron system. We show an enhancement of the minority-spin many-body velocity renormalization at fully spin polarization due to reduction in the electron density and consequently increase in the interaction between electrons near the Fermi surface. We also show that the spin dependence of the Fermi velocity in the chiral Fermi systems is different than that in a conventional two-dimensional electron liquid. In addition, we show that the ratio of the majority- to minority-spin lifetime is smaller than unity and related directly to the polarization and electron energy. The spin-polarization dependence of the carrier Fermi velocity is of significance in various spintronic applications.Comment: 9 pages, 6 figures. To appear in Phys. Rev.

Anisotropic RKKY interaction in spin-polarized graphene

“…This stable crystal has already attracted considerable attention because of its unusual effective many-body properties [6][7][8][9][10][11][12][13] that follow from chiral nature of linearly dispersing low energy excitations described by pair of Dirac cones at the K and K edges of the first Brillouin zone.…”

Review on graphene spintronic, new land for discovery

“…However, as we mentioned in section 1-2-1 metals have short spin relaxation time, so finding appropriate semiconductor material is attractive [3,30,56,144,155,156]. In addition, stable nonreactive graphene layers on top of FM materials might be used as sources of spin-polarized electrons [157]. SLG spin relaxation time increases proportional to carrier density, independent of thermal fluctuation.…”

Electronic ground state properties of strained graphene

“…The Fermi velocity is an essential quantity in graphene because all the observable quantities depend on it. For the Dirac electrons in pristine graphene, it was shown [15][16][17][18][19][20] that interaction effects also become noticeable with decreasing density in that the velocity is enhanced rather than suppressed, and that the influence of interactions on the compressibility and the spinsusceptibility changes sign. These qualitative differences are due to exchange interactions between electrons near the Fermi surface and electrons in the negative energy sea and to interband contributions to Dirac electrons from charge and spin fluctuations.…”