Voltage-dependent spin flip in magnetically-substituted graphene   nanoribbons: Toward the realization of graphene-based spintronic devices
  We examine the possibility of using graphene nanoribbons (GNRs) with directly substituted chromium atoms as spintronic device. Using density functional theory, we simulate a voltage bias across a constructed GNR in a device setup, where a magnetic dimer has been substituted into the lattice. Through this first principles approach, we calculate the electronic and magnetic properties as a function of Hubbard U, voltage, and magnetic configuration. By calculating of the total energy of each magnetic configuration, we determine that initial antiferromagnetic ground state flips to a ferromagnetic state with applied bias. Mapping this transition point to the calculated conductance for the system reveals that there is a distinct change in conductance through the GNR, which indicates the possibility of a spin valve. We also show that this corresponds to a distinct change in the induced magnetization within the graphene. 
Gregory Houchins, Charles B. Crook, Jian-Xin Zhu, Alexander V.   Balatsky, and Jason T. Haraldsen
cond-mat.mtrl-sci cond-mat.mes-hall cond-mat.str-el