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arXiv · 1007.4743

Mean-field quantum phase transition in graphene and in general gapless systems

Ádám Bácsi·Attila Virosztek·László Borda·Balázs Dóra
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Abstract

We study the quantum critical properties of antiferromagnetism in graphene at T=0 within mean-field (MF) theory. The resulting exponents differ from the conventional MF exponents, describing finite temperature transitions. Motivated by this, we have developed the MF theory of general gapless phases with density of states rho(E) |E|^r, r>-1, with the interaction as control parameter. For r>2, the conventional MF exponents á la Landau are recovered, while for -1 0, therefore no weak-coupling solution exists in this range. This generalizes the results on quantum criticality of the gapless Kondo systems to bulk correlated phases.

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Ádám Bácsi, Attila Virosztek, László Borda, Balázs Dóra. 2010-07-27. Mean-field quantum phase transition in graphene and in general gapless systems. https://doi.org/10.1103/physrevb.82.153406

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