2015/12/15 by Una Karahasanovic, Jörg Schmalian, Joerg Schmalian · 46 citations
Business, Management and Accounting · Materials Science · Physics and Astronomy · #Biaxial nematic #Condensed matter physics #Corporate Taxation and Avoidance #Coupling (piping) #Degrees of freedom (physics and chemistry) #Iron-based superconductors research #Liquid crystal #Materials science #Mean field theory #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Spin (aerodynamics) #Superconductivity #Thermodynamics #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.93.064520
published in Physical review. B./Physical review. B 93(6) (American Physical Society) · 9 pages, 4 figures
arxiv created 2015/12/15 · openalex publication_date 2016/02/26 · arxiv updated 2016/03/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Spin-driven nematic order that has been proposed for iron-based superconductors is generated by pronounced fluctuations of a striped density wave state. On the other hand it is a well known fact that the nematic order parameter couples bilinearly to the strain, which suppresses the fluctuations of the nematic order parameter itself and lowers the upper critical dimension, yielding mean-field behavior of the nematic degrees of freedom for d>2. This is consistent with the measured Curie-Weiss behavior of the nematic susceptibility. Here we reconcile this apparent contradiction between pronounced magnetic fluctuations and mean-field behavior of the nematic degrees of freedom. We show, by developing a \ensuremathφ4 theory for the nematic degrees of freedom, that the coupling to elastic strain does not suppress the fluctuations that cause the nematic order in the first place (magnetic fluctuations), yet it does transform the Ising-nematic transition into a mean-field transition. In addition, we demonstrate that the mean-field behavior occurs in the entire temperature regime where a softening of the shear modulus is observed.