Departamento de Física Aplicada, Universidad de Alicante, San Vicente del Raspeig, Spain.
Phys Rev Lett. 2011 Jul 1;107(1):016602. doi: 10.1103/PhysRevLett.107.016602. Epub 2011 Jun 30.
Spin-dependent features in the conductivity of graphene, chemically modified by a random distribution of hydrogen adatoms, are explored theoretically. The spin effects are taken into account using a mean-field self-consistent Hubbard model derived from first-principles calculations. A Kubo transport methodology is used to compute the spin-dependent transport fingerprints of weakly hydrogenated graphene-based systems with realistic sizes. Conductivity responses are obtained for paramagnetic, antiferromagnetic, or ferromagnetic macroscopic states, constructed from the mean-field solutions obtained for small graphene supercells. Magnetoresistance signals up to ∼7% are calculated for hydrogen densities around 0.25%. These theoretical results could serve as guidance for experimental observation of induced magnetism in graphene.
本文理论研究了通过随机分布的氢原子修饰的石墨烯的电导率中的自旋相关特征。自旋效应是通过从第一性原理计算得出的平均场自洽 Hubbard 模型来考虑的。使用 Kubo 输运方法计算了具有实际尺寸的弱氢化石墨烯基系统的自旋相关输运指纹。对于由从小石墨烯超胞获得的平均场解构造的顺磁、反铁磁或铁磁宏观态，得到了电导率响应。对于约 0.25%的氢密度，计算出高达约 7%的磁电阻信号。这些理论结果可以为实验观测石墨烯中的诱导磁性提供指导。
