Abstract
Using Monte Carlo simulations with a tunable uniaxial strain, the nematic susceptibility of the spin fermion model for the pnictides is calculated. The results are in excellent agreement with the experiments by Chu et al. [Science 337, 710 (2012)]. Via a Ginzburg-Landau analysis, our study suggests a nematicity in the spin fermion model primarily originating in magnetism, but with the lattice/orbital also playing a key role by boosting up critical temperatures and separating the structural and Néel transitions. At , Curie-Weiss behavior is observed with a characteristic temperature being the of the purely electronic system. In this temperature regime, short-range magnetic order with wave vectors induce local nematic fluctuations and a density-of-states pseudogap, compatible with several experiments. The present analysis relies on the study of a particular model for the iron superconductors; thus further studies are needed to conclusively establish the driver of nematicity in real materials.
- Received 23 May 2014
- Revised 20 October 2014
DOI:https://doi.org/10.1103/PhysRevB.90.184507
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