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arXiv · 1010.2940

Theory of Orbital Nematicity in Underdoped Iron Arsenides

Mukul S. Laad·Luis Craco
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Abstract

Recent finding of an {\it unusual} in-plane resistivity anisotropy in the underdoped 122-family at high temperature ($T$) suggests an orbital nematic (ON) order, posing a challenge to extant theories. The {\it sign} of the anisotropy contradicts expectations from weakly correlated as well as pure spin-only nematic views. Here, we show how such an ON order with accompanying structural distortion arises from {\it residual}, intersite and inter-orbital two-body interactions in an incoherent "bad metal" close to Mottness. Enhancement of orbital-selective incoherence is shown to be necessary for understanding transport anisotropy. Our results suggest that ON order, with subsequent antiferromagnetic order might be the {\it primary} competitor to superconductivity in Fe arsenides.

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Mukul S. Laad, Luis Craco. 2010-10-14. Theory of Orbital Nematicity in Underdoped Iron Arsenides. https://arxiv.org/abs/1010.2940

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