Diverging nematic susceptibility, physical meaning of T* scale, and pseudogap in the spin fermion model for the pnictides

作者：Liang Shuhua^*; Mukherjee Anamitra; Patel Niravkumar D; Bishop Christopher B; Dagotto Elbio; Moreo Adriana

来源：Physical Review B, 2014, 90(18): 184507.

DOI：10.1103/PhysRevB.90.184507

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 T-S and Neel T-N transitions. At T > T-S, Curie-Weiss behavior is observed with a characteristic temperature T* being the T-N of the purely electronic system. In this temperature regime, short-range magnetic order with wave vectors (pi, 0)-(0, pi) 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.

• 出版日期2014-11-12