Anisotropic and quasipropagating spin excitations in superconducting Ba(Fe(0.926)Co(0.074))(2)As(2)

作者：Li H F^*; Broholm C; Vaknin D; Fernandes R M; Abernathy D L; Stone M B; Pratt D K; Tian W; Qiu Y; Ni N; Diallo S O; Zarestky J L; Bud'; ko S L; Canfield P C; McQueeney R J

来源：Physical Review B, 2010, 82(14): 140503.

DOI：10.1103/PhysRevB.82.140503

Inelastic neutron scattering from superconducting (SC) Ba (Fe(0.926)Co(0.074))(2)As(2) reveals anisotropic and quasi-two-dimensional (2D) magnetic excitations close to Q(AFM)=(1/21/2) - the 2D antiferromagnetic (AFM) wave vector of the parent BaFe(2)As(2) compound. The correlation length anisotropy of these low-energy fluctuations is consistent with spin nematic correlations in the J(1)-J(2) model with J(1)/J(2)similar to 1. The spin resonance at similar to 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 Q(AFM) above similar to 80 meV indicating unusual quasipropagating excitations.

• 出版日期2010-10-12