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Electron-electron interactions and the phase diagram of a graphene bilayer

Johan Nilsson·A. H. Castro Neto·N. M. R. Peres·F. Guinea
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Abstract

We study the effects of long and short-range electron-electron interactions in a graphene bilayer. Using a variational wavefunction technique we show that in the presence of long-range Coulomb interactions the clean bilayer is always unstable to electron and hole pocket formation with a finite ferromagnetic polarization. Furthermore, we argue that short-range electron-electron interactions lead to a staggered orientation of the ordered ferromagnetic moment in each layer (that is, c-axis antiferromagnetism). We also comment on the effects of doping and trigonal distortions of the electronic bands.

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Johan Nilsson, A. H. Castro Neto, N. M. R. Peres, F. Guinea. 2006-12-18. Electron-electron interactions and the phase diagram of a graphene bilayer. https://doi.org/10.1103/physrevb.73.214418

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