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arXiv · 0808.2720

Quantum Phase Transition in a Graphene Model

Simon Hands·Costas Strouthos
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Abstract

We present results for the equation of state of a graphene-like model in an effort to understand the properties of its quantum phase transition. The N_f fermion species interact through a three dimensional instantaneous Coulomb potential. Since there are no reliable analytical tools that work for all values of N_f and the coupling constant g, we rely on Monte Carlo simulations to calculate the critical properties of the model near the phase transition. We consider the four-component formulation for the fermion fields, which arises naturally as the continuum limit of the staggered fermion construction in (2+1) dimensions. In the limit of infinitely strong Coulomb interaction, the system undergoes a quantum phase transition at a critical number of fermion species N_fc ~ 4.7. We also calculate the values of the critical exponents at the quantum phase transition.

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Simon Hands, Costas Strouthos. 2008-08-20. Quantum Phase Transition in a Graphene Model. https://doi.org/10.1088/1742-6596/150/4/042191

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