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arXiv · 0902.3242

Evolution of pairing from weak to strong coupling on a honeycomb lattice

Shi-Quan Su·Ka-Ming Tam·Hai-Qing Lin
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Abstract

We study the evolution of the pairing from weak to strong coupling on a honeycomb lattice by Quantum Monte Carlo. We show numerical evidence of the BCS-BEC crossover as the coupling strength increases on a honeycomb lattice with small fermi surface by measuring a wide range of observables: double occupancy, spin susceptibility, local pair correlation, and kinetic energy. Although at low energy, the model sustains Dirac fermions, we do not find significant qualitative difference in the BCS-BEC crossover as compared to those with an extended Fermi surface, except at weak coupling, BCS regime.

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Shi-Quan Su, Ka-Ming Tam, Hai-Qing Lin. 2009-02-18. Evolution of pairing from weak to strong coupling on a honeycomb lattice. https://doi.org/10.1103/physrevb.80.104517

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