Nematicity driven by hybridization in iron-based superconductors
Abstract
In this Rapid Communication, we study an effective model for the normal state of iron-based superconductors. It has separate but interacting itinerant and localized degrees of freedom, originating from the dxz and dyz and from the dxy iron orbitals, respectively. At low temperatures, below a mean-field phase transition, these different states condense together in an excitonic order parameter. We show that, at even lower temperatures, after another phase transition, this ordered state can spontaneously break the C4 lattice symmetry and become nematic. We propose this mechanism as an explanation of the tendency towards nematicity observed in several iron-based compounds.
- Publication:
-
Physical Review B
- Pub Date:
- April 2013
- DOI:
- 10.1103/PhysRevB.87.161122
- arXiv:
- arXiv:1302.5739
- Bibcode:
- 2013PhRvB..87p1122S
- Keywords:
-
- 74.70.Xa;
- 74.20.Mn;
- Nonconventional mechanisms;
- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Superconductivity
- E-Print:
- 5 pages, 3 figures, new references added, replaced Fig. 1, fixed several typos