Universal linear-temperature dependence of static magnetic susceptibility in iron pnictides

¹  Department of Physics, Tsinghua University - Beijing 100084, China
²  Department of Physics, Yantai University - Yantai 264005, China
³  Department of Physics, Renmin University of China - Beijing 100872, China
⁴  Center for Advanced Study, Tsinghua University - Beijing 100084, China
⁵  Department of Physics, University of California at Berkeley - Berkeley, CA 94720, USA
⁶  Institute of Physics, Chinese Academy of Sciences - Beijing 100190, China
⁷  Institute of Theoretical Physics, Chinese Academy of Sciences - Beijing 100190, China

Corresponding author: gmzhang@tsinghua.edu.cn

Received: 11 November 2008
Accepted: 17 April 2009

Abstract

A universal linear-temperature dependence of the uniform magnetic susceptibility has been observed in the non-magnetic normal state of iron pnictides. This non-Pauli and non-Curie-Weiss-like paramagnetic behavior cannot be understood within a simple mean-field picture. We argue that it results from the existence of a wide antiferromagnetic fluctuation window in which the local spin-density-wave correlations exist but the global directional order has not been established yet.