Phase separation of antiferromagnetic ground states in systems with imperfect nesting

Abstract

We analyze the phase diagram for a system of weakly-coupled electrons having an electron- and a hole-band with imperfect nesting. Namely, both bands have spherical Fermi surfaces, but their radii are slightly different, with a mismatch proportional to the doping. Such a model is used to describe: the antiferromagnetism of chromium and its alloys, pnictides, AA-stacked graphene bilayers, as well as other systems. Here we show that the uniform ground state of this model is unstable with respect to electronic phase separation in a wide range of model parameters. Physically, this instability occurs due to the competition between commensurate and incommensurate antiferromagnetic states and could be of importance for other models with imperfect nesting.

7 pages, 4 eps figures, in this version minor misprints are corrected, new references are added

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Cited by in corpus (7)

• Electronic phase separation: recent progress in the old problem
• Metal-insulator transition and phase separation in doped AA-stacked graphene bilayers
• Magnetic field effects in electron systems with imperfect nesting
• Ordering in SU(4)-symmetric model of AA bilayer graphene
• Coexistence of nematic superconductivity and spin density wave in magic-angle twisted bilayer graphene
• First-order phase transition between superconductivity and charge/spin-density wave as the reason of their coexistence in organic metals
• Canted antiferromagnetism and excitonic order in gated double-layer graphene