Itinerant Magnetic Excitations in Antiferromagnetic CaFe2As2

TitleItinerant Magnetic Excitations in Antiferromagnetic CaFe2As2
Publication TypeJournal Article
Year of Publication2009
AuthorsDiallo SO, Antropov VP, Perring TG, Broholm C, Pulikkotil JJ, Ni N, Bud'ko SL, Canfield PC, Kreyssig A, Goldman AI, McQueeney RJ
Journal TitlePhysical Review Letters
Volume102
Pages187206
Date Published05/08
ISBN Number0031-9007
Accession NumberISI:000265948600066
Abstract

Neutron scattering measurements of the magnetic excitations in single crystals of antiferromagnetic CaFe2As2 reveal steeply dispersive and well-defined spin waves up to an energy of similar to 100 meV. Magnetic excitations above 100 meV and up to the maximum energy of 200 meV are however broader in energy and momentum than the experimental resolution. While the low energy modes can be fit to a Heisenberg model, the total spectrum cannot be described as arising from excitations of a local moment system. Ab initio calculations of the dynamic magnetic susceptibility suggest that the high energy behavior is dominated by the damping of spin waves by particle-hole excitations.

URL<Go to ISI>://000265948600066
DOI10.1103/Physrevlett.102.187206