Inelastic neutron scattering study of a nonmagnetic collapsed tetragonal phase of CaFe2As2: Evidence of the impact of spin fluctuations on superconductivity in the iron-arsenide compounds.

Journal Article · Tue Jan 01 00:00:00 EST 2013 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.111.227002· OSTI ID:1110956

Soh, Jing Han ^[1]; Tucker, G. S. ^[2]; Pratt, Daniel K ^[1]; Abernathy, Douglas L ^[1]; Stone, Matthew B ^[1]; Ran, S. ^[2]; Budko, S L ^[2]; Canfield, P. C. ^[3]; Kreyssig, A. ^[2]; McQueeney, R. J. ^[3]; Goldman, A. I. ^[2]

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1. ORNL
2. Ames Laboratory and Iowa State University
3. Ames Laboratory

The relationship between antiferromagnetic spin fluctuations and superconductivity has become a central topic of research in studies of superconductivity in the iron pnictides. We present unambiguous evidence of the absence of magnetic fluctuations in the non-superconducting collapsed tetragonal phase of CaFe2As2 via inelas- tic neutron scattering time-of-flight data, which is consistent with the view that spin fluctuations are a necessary ingredient for unconventional superconductivity in the iron pnictides. We demonstrate that the collapsed tetrag- onal phase of CaFe2As2 is non-magnetic, and discuss this result in light of recent reports of high-temperature superconductivity in the collapsed tetragonal phase of closely related compounds.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1110956
• Journal Information: Physical Review Letters, Vol. 111, Issue 22; ISSN 0031--9007
• Country of Publication: United States
• Language: English