Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232, Villigen PSI, Switzerland.
Laboratory for Scientific Developments and Novel Materials, Paul Scherrer Institut, 5232, Villigen PSI, Switzerland.
Sci Rep. 2018 Jan 22;8(1):1295. doi: 10.1038/s41598-018-19555-z.
NdCeCoIn features a magnetic field-driven quantum phase transition that separates two antiferromagnetic phases with an identical magnetic structure inside the superconducting condensate. Using neutron diffraction we demonstrate that the population of the two magnetic domains in the two phases is affected differently by the rotation of the magnetic field in the tetragonal basal plane. In the low-field SDW-phase the domain population is only weakly affected while in the high-field Q-phase they undergo a sharp switch for fields around the a-axis. Our results provide evidence that the anisotropic spin susceptibility in both phases arises ultimately from spin-orbit interactions but are qualitatively different in the two phases. This provides evidence that the electronic structure is changed at the quantum phase transition, which yields a modified coupling between magnetism and superconductivity in the Q-phase.
NdCeCoIn 具有磁场驱动的量子相变，它将超导凝聚体内具有相同磁结构的两个反铁磁相分开。使用中子衍射，我们证明了在四方基面内磁场旋转对两个相中的两个磁畴的分布有不同的影响。在低场 SDW 相中，磁畴的分布受影响较弱，而在高场 Q 相中，当磁场绕 a 轴旋转时，它们会发生急剧的转变。我们的结果提供了证据表明，两个相中的各向异性自旋磁化率最终都源于自旋轨道相互作用，但在两个相中的性质不同。这表明电子结构在量子相变中发生了变化，这导致了 Q 相中美磁耦合的改变。
