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arXiv · 1210.6973

Ab Initio Many-body Study of Cobalt Adatoms Adsorbed on Graphene

Yudistira Virgus·Wirawan Purwanto·Henry Krakauer·Shiwei Zhang
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Abstract

Many recent calculations have been performed to study a Co atom adsorbed on graphene, with significantly varying results on the nature of the bonding. We use auxiliary-field quantum Monte Carlo (AFQMC) and a size-correction embedding scheme to accurately calculate the binding energy of Co on graphene. We find that as a function of the distance h between the Co atom and the six-fold hollow site, there are three distinct ground states corresponding to three electronic configurations of the Co atom. Two of these states provide binding and exhibit a double-well feature with nearly equal binding energy of 0.4 eV at h = 1.51 and h = 1.65 angstroms, corresponding to low-spin $^2$Co (3d9 4s0) and high-spin $^4$Co (3d8 4s1), respectively.

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Yudistira Virgus, Wirawan Purwanto, Henry Krakauer, Shiwei Zhang. 2012-10-25. Ab Initio Many-body Study of Cobalt Adatoms Adsorbed on Graphene. https://doi.org/10.1103/physrevb.86.241406

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