Strength of Effective Coulomb Interactions in Graphene and Graphite
Strength of Effective Coulomb Interactions in Graphene and Graphite
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DOI：
10.1103/physrevlett.106.236805
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发表时间：
2011-06-08
影响因子：
8.6
通讯作者：
Bluegel, S.
中科院分区：
文献类型：
--
作者：
Wehling, T. O.;Sasioglu, E.;Bluegel, S.
为了从第一性原理得到石墨烯及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，有效的现场（哈伯德）相互作用是U-00 = 9.3 eV，非常接近将导电石墨烯与绝缘相分离的临界值，强调了非局部库仑项的重要性。最近邻库仑相互作用强度计算为U-01 = 5.5 eV。在长波长范围内，我们发现石墨的有效背景介电常数是= 2.5的元素，与实验非常吻合。
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 is an element of = 2.5 in very good agreement with experiment.