Anisotropic and quasipropagating spin excitations in superconducting Ba(Fe0.926Co0.074)(2)As-2

Li, H.-F.; Broholm, C.; Vaknin, David; Fernandes, R. M.; Abernathy, D. L.; Stone, M. B.; Pratt, D. K.; Tian, W.; Qiu, Y.; Ni, Ni; Diallo, S. O.; Zarestky, J. L.; Bud’ko, Sergey; Canfield, Paul; McQueeney, Robert

Anisotropic and quasipropagating spin excitations in superconducting Ba(Fe0.926Co0.074)(2)As-2

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2010_CanfieldPaul_AnisotropicQuasipropagating.pdf (533.35 KB)

Date

2010-10-01

Authors

Li, H.-F.

Broholm, C.

Vaknin, David

Fernandes, R. M.

Abernathy, D. L.

Stone, M. B.

Pratt, D. K.

Tian, W.

Qiu, Y.

Ni, Ni

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Abstract

Inelastic neutron scattering from superconducting (SC) Ba(Fe0.926Co0.074)2As2 reveals anisotropic and quasi-two-dimensional (2D) magnetic excitations close to QAFM=(1212) - the 2D antiferromagnetic (AFM) wave vector of the parent BaFe2As2 compound. The correlation length anisotropy of these low-energy fluctuations is consistent with spin nematic correlations in the J1−J2 model with J1/J2∼1. The spin resonance at ∼8.3 meV in the SC state displays the same anisotropy. The anisotropic fluctuations experimentally evolve into two distinct maxima only along the direction transverse to QAFM above ∼80 meV indicating unusual quasipropagating excitations.

Academic or Administrative Unit

Ames National Laboratory

Physics and Astronomy

Ames Laboratory

Type

article

Comments

This article is published as Li, H-F., Collin Broholm, David Vaknin, Rafael M. Fernandes, D. L. Abernathy, M. B. Stone, D. K. Pratt, W. Tian, Y. Qiu, N. Ni, S. O. Diallo, J. L. Zarestky, S. L. Bud’ko, P. C. Canfield, and R. J. McQueeney. "Anisotropic and quasipropagating spin excitations in superconducting Ba (Fe 0.926 Co 0.074) 2 As 2." Physical Review B 82, no. 14 (2010): 140503(R). DOI: 10.1103/PhysRevB.82.140503.