Abstract
Inelastic neutron scattering from superconducting (SC) Ba (Fe 0.926 Co0.074)2 As2 reveals anisotropic and quasi-two-dimensional (2D) magnetic excitations close to Q AFM = (1 2 1 2) - the 2D antiferromagnetic (AFM) wave vector of the parent BaFe2 As2 compound. The correlation length anisotropy of these low-energy fluctuations is consistent with spin nematic correlations in the J1-J2 model with J1/J 2 ∼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.
Original language | English |
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Article number | 140503 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 82 |
Issue number | 14 |
DOIs | |
State | Published - Oct 12 2010 |