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arXiv · 2010.11090

Can bilayer graphene become a fractional metal?

A. O. Sboychakov·A. L. Rakhmanov·A. V. Rozhkov·Franco Nori
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Abstract

It is known that electron interactions can cause a perfect spin polarization of the Fermi surface of a metal. In such a situation only half of the non-interacting Fermi surface is available, and thus this phase is commonly referred to as a 'half-metal'. Here we argue that, in multi-band electronic systems with nesting, further 'fractionalization' of the Fermi surface is possible. Taking the AA bilayer graphene as a convenient test case, we demonstrate that, under suitable conditions imposed on the electron interactions, doped AA bilayer graphene can host a 'quarter-metal' state. In such a state, only one quarter of the non-interacting Fermi surface (Fermi contour) reaches the Fermi energy. At higher doping level, other 'fractional' metals can emerge. We briefly analyze the transport properties of these proposed phases.

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A. O. Sboychakov, A. L. Rakhmanov, A. V. Rozhkov, Franco Nori. 2020-10-21. Can bilayer graphene become a fractional metal?. https://doi.org/10.1103/physrevb.103.l081106

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