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arXiv · 1306.3258

Dimerized Solids and Resonating Plaquette Order in SU(N)-Dirac Fermions

Thomas C. Lang·Zi Yang Meng·Alejandro Muramatsu·Stefan Wessel·Fakher F. Assaad
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Abstract

We study the quantum phases of fermions with an explicit SU(N)-symmetric, Heisenberg-like nearest-neighbor flavor exchange interaction on the honeycomb lattice at half-filling. Employing projective (zero temperature) quantum Monte Carlo simulations for even values of N, we explore the evolution from a weak-coupling semimetal into the strong-coupling, insulating regime. Furthermore, we compare our numerical results to a saddle-point approximation in the large-N limit. From the large-N regime down to the SU(6) case, the insulating state is found to be a columnar valence bond crystal, with a direct transition to the semimetal at weak, finite coupling, in agreement with the mean-field result in the large-N limit. At SU(4) however, the insulator exhibits a subtly different valence bond crystal structure, stabilized by resonating valence bond plaquettes. In the SU(2) limit, our results support a direct transition between the semimetal and an antiferromagnetic insulator.

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Thomas C. Lang, Zi Yang Meng, Alejandro Muramatsu, Stefan Wessel, Fakher F. Assaad. 2013-06-13. Dimerized Solids and Resonating Plaquette Order in SU(N)-Dirac Fermions. https://doi.org/10.1103/physrevlett.111.066401

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