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arXiv · 1105.2469

Macroscopic Degeneracy and Emergent Frustration in a Honeycomb Lattice Magnet

Jörn W. F. Venderbos·Maria Daghofer·Jeroen van den Brink·Sanjeev Kumar
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Abstract

Using a hybrid method based on fermionic diagonalization and classical Monte Carlo, we investigate the interplay between itinerant and localized spins, with competing double- and super-exchange interactions, on a honeycomb lattice. For moderate superexchange, a geometrically frustrated triangular lattice of hexagons forms spontaneously. For slightly larger superexchange a dimerized groundstate is stable that has macroscopic degeneracy. The presence of these states on a non-frustrated honeycomb lattice highlights a novel phenomenon in this itinerant electron system: emergent geometrical frustration and degeneracy.

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Jörn W. F. Venderbos, Maria Daghofer, Jeroen van den Brink, Sanjeev Kumar. 2011-09-09. Macroscopic Degeneracy and Emergent Frustration in a Honeycomb Lattice Magnet. https://doi.org/10.1103/physrevlett.107.076405

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