Back to Search
Start Over
Microscopic Theory of Magnetic Detwinning in Iron-Based Superconductors with Large-Spin Rare Earths
- Source :
- Physical Review X, Vol 8, Iss 1, p 011011 (2018)
- Publication Year :
- 2018
- Publisher :
- American Physical Society, 2018.
-
Abstract
- Detwinning of magnetic (nematic) domains in Fe-based superconductors has so far only been obtained through mechanical straining, which considerably perturbs the ground state of these materials. The recently discovered nonmechanical detwinning in EuFe_{2}As_{2} by ultralow magnetic fields offers an entirely different, nonperturbing way to achieve the same goal. However, this way seemed risky due to the lack of a microscopic understanding of the magnetically driven detwinning. Specifically, the following issues remained unexplained: (i) ultralow value of the first detwinning field of approximately 0.1 T, two orders of magnitude below that of BaFe_{2}As_{2}, and (ii) reversal of the preferential domain orientation at approximately 1 T and restoration of the low-field orientation above 10–15 T. In this paper, we present, using published as well as newly measured data, a full theory that quantitatively explains all the observations. The key ingredient of this theory is a biquadratic coupling between Fe and Eu spins, analogous to the Fe-Fe biquadratic coupling that drives the nematic transition in this family of materials.
Details
- Language :
- English
- ISSN :
- 21603308
- Volume :
- 8
- Issue :
- 1
- Database :
- Directory of Open Access Journals
- Journal :
- Physical Review X
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.13f645c0b42f46b28b86579c15823a6e
- Document Type :
- article
- Full Text :
- https://doi.org/10.1103/PhysRevX.8.011011