標題: Hyperfine Fields and Magnetic Structure in the B Phase of CeCoIn(5)
作者: Curro, Nicholas J.
Young, Ben-Li
Urbano, Ricardo R.
Graf, Matthias J.
電子物理學系
Department of Electrophysics
公開日期: 1-Feb-2010
摘要: We re-analyze Nuclear Magnetic Resonance (NMR) spectra observed at low temperatures and high magnetic fields in the field-induced B phase of CeCoIn(5). The NMR spectra are consistent with incommensurate antiferromagnetic order of the Ce magnetic moments. However, we find that the spectra of the In(2) sites depend critically on the direction of the ordered moments, the ordering wavevector and the symmetry of the hyperfine coupling to the Ce spins. Assuming isotropic hyperfine coupling, the NMR spectra observed for H parallel to [100] are consistent with magnetic order with wavevector Q = pi (1+delta/a, 1/a, 1/c) and Ce moments ordered antiferromagnetically along the [100] direction in real space. If the hyperfine coupling has dipolar symmetry, then the NMR spectra require Ce moments along the [ 001] direction. The dipolar scenario is also consistent with recent neutron scattering measurements that find an ordered moment of 0.15 mu(B) along [001] and Q(n) = pi(1+delta/a, 1+delta/a, 1/c) with in-commensuration delta = 0.12 for field H parallel to [1 (1) over bar0]. Using these parameters, we find that a hyperfine field with dipolar contribution is consistent with findings from both experiments. We speculate that the B phase of CeCoIn(5) represents an intrinsic phase of modulated superconductivity and antiferromagnetism that can only emerge in a highly clean system.
URI: http://dx.doi.org/10.1007/s10909-009-9967-y
http://hdl.handle.net/11536/5918
ISSN: 0022-2291
DOI: 10.1007/s10909-009-9967-y
期刊: JOURNAL OF LOW TEMPERATURE PHYSICS
Volume: 158
Issue: 3-4
起始頁: 635
結束頁: 646
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