Campus Units
Physics and Astronomy, Ames Laboratory
Document Type
Article
Publication Version
Published Version
Publication Date
5-1-2014
Journal or Book Title
Physical Review B
Volume
89
Issue
18
First Page
180503(R)
DOI
10.1103/PhysRevB.89.180503
Abstract
Using inelastic neutron scattering, we show that the onset of superconductivity in underdoped Ba(Fe1−xCox)2As2 coincides with a crossover from well-defined spin waves to overdamped and diffusive spin excitations. This crossover occurs despite the presence of long-range stripe antiferromagnetic order for samples in a compositional range from x=0.04 to 0.055, and is a consequence of the shrinking spin-density wave gap and a corresponding increase in the particle-hole (Landau) damping. The latter effect is captured by a simple itinerant model relating Co doping to changes in the hot spots of the Fermi surface. We argue that the overdamped spin fluctuations provide a pairing mechanism for superconductivity in these materials.
Copyright Owner
American Physical Society
Copyright Date
2014
Language
en
File Format
application/pdf
Recommended Citation
Tucker, G. S.; Fernandes, R. M.; Pratt, D. K.; Thaler, A.; Ni, N.; Marty, K.; Christianson, A. D.; Lumsden, M. D.; Sales, B. C.; Sefat, A. S.; Bud’ko, Sergey L.; Canfield, Paul C.; Kreyssig, Andreas; Goldman, Alan I.; and McQueeney, Robert J., "Crossover from spin waves to diffusive spin excitations in underdoped Ba(Fe1-xCox)(2)As-2" (2014). Physics and Astronomy Publications. 600.
https://lib.dr.iastate.edu/physastro_pubs/600
Comments
This article is published as Tucker, G. S., R. M. Fernandes, D. K. Pratt, A. Thaler, N. Ni, K. Marty, Andrew D. Christianson, M. D. Lumsden, B. C. Sales, A. S. Sefat, S. L. Bud’ko, P. C. Canfield, A. Kreyssig, A. I. Goldman, and R. J. McQueeney. "Crossover from spin waves to diffusive spin excitations in underdoped Ba (Fe 1− x Co x) 2 As 2." Physical Review B 89, no. 18 (2014): 180503. DOI: 10.1103/PhysRevB.89.180503. Posted with permission.