Centre de Physique Théorique, Ecole Polytechnique, CNRS-UMR7644, 91128 Palaiseau, France.
J Phys Condens Matter. 2013 Mar 6;25(9):094005. doi: 10.1088/0953-8984/25/9/094005. Epub 2013 Feb 12.
Electronic correlations together with dimensional constraints lead to some of the most fascinating properties known in condensed matter physics. As possible candidates where these conditions are realized, semiconductor (111) surfaces and adatom systems on surfaces have been under investigation for quite some time. However, state-of-the-art theoretical studies on these materials that include many-body effects beyond the band picture are rare. First principles estimates of inter-electronic Coulomb interactions for the correlated states are missing entirely, and usually these interactions are treated as adjustable parameters. In this work, we report on calculations of the interaction parameters for the group IV surface-adatom systems in the α-phase series of Si(111):C, Si, Sn, Pb. For all systems investigated, the inter-electronic Coulomb interactions are indeed large compared to the kinetic energies of the states in question. Moreover, our study reveals that intersite interactions cannot be disregarded. We explicitly construct an extended Hubbard model for the series of group IV surface-adatom systems on silicon, which can be used for further many-body calculations.
电子相关和维度约束导致了凝聚态物理中一些最引人入胜的性质。半导体（111）表面和表面上的吸附原子体系是这些条件得以实现的可能候选物，因此它们已经被研究了很长一段时间。然而，包括能带图之外的多体效应的这些材料的最先进的理论研究却很少。对于相关态的电子间库仑相互作用，没有完全的第一性原理估计，通常这些相互作用被视为可调参数。在这项工作中，我们报告了对 Si(111)：C、Si、Sn、Pb 的α相系列中 IV 族表面吸附原子体系的相互作用参数的计算。对于所有被研究的体系，电子间库仑相互作用确实远远大于所讨论的态的动能。此外，我们的研究表明，不能忽略相间相互作用。我们为硅上的 IV 族表面吸附原子体系系列明确构建了一个扩展的 Hubbard 模型，可用于进一步的多体计算。
