Institut für Theoretische Physik, Universität Hamburg, Hamburg, Germany.
Phys Rev Lett. 2011 Jun 10;106(23):236805. doi: 10.1103/PhysRevLett.106.236805. Epub 2011 Jun 8.
To obtain an effective many-body model of graphene and related materials from first principles we calculate the partially screened frequency dependent Coulomb interaction. In graphene, the effective on-site (Hubbard) interaction is U(00)=9.3 eV in close vicinity to the critical value separating conducting graphene from an insulating phase emphasizing the importance of nonlocal Coulomb terms. The nearest-neighbor Coulomb interaction strength is computed to U(01)=5.5 eV. In the long-wavelength limit, we find the effective background dielectric constant of graphite to be ϵ=2.5 in very good agreement with experiment.
为了从第一性原理获得石墨烯和相关材料的有效多体模型，我们计算了部分屏蔽的频率相关库仑相互作用。在石墨烯中，有效局域（哈伯德）相互作用 U(00)=9.3 eV 非常接近分离导电石墨烯和绝缘相的临界值，强调了非局域库仑项的重要性。计算得到最近邻库仑相互作用强度 U(01)=5.5 eV。在长波长极限下，我们发现石墨的有效背景介电常数为 ϵ=2.5，与实验非常吻合。
