论文标题
在双层超导体CSCA2FE4AS4F2中观察中子自旋共振
Observation of a neutron spin resonance in the bilayered superconductor CsCa2Fe4As4F2
论文作者
论文摘要
我们报告了对基于双层Fe的超导体CSCA2FE4AS4F4的非弹性中子散射（INS）研究，其超导过渡温度TC = 28.9 K，以研究中子自旋共振的存在。这种复合在一个以身体为中心的四方晶格中结晶，其中包含通过绝缘CAF2层隔开的Fe2AS2的不对称双层，并且已知高度各向异性。我们的INS研究清楚地揭示了中子自旋共振的存在，该共振在较低的动量转移（Q）时在5K时表现出较高的强度，而54 K的能量为15 MeV。观察到的自旋共振的能量ER与关系E_R = 4.9 k_b t_c的关系大致一致，但是与在基于Fe的基于Fe的超导体中观察到的值相比，相比之下。我们通过将E_R的值与从费米表面上集成的总超导差距值进行比较，讨论了电子配对对称性的性质。
We report inelastic neutron scattering (INS) investigations on the bilayer Fe-based superconductor CsCa2Fe4As4F4 above and below its superconducting transition temperature Tc = 28.9 K to investigate the presence of a neutron spin resonance. This compound crystallises in a body-centred tetragonal lattice containing asymmetric double layers of Fe2As2 separated by insulating CaF2 layers and is known to be highly anisotropic. Our INS study clearly reveals the presence of a neutron spin resonance that exhibits higher intensity at lower momentum transfer (Q) at 5K compared to 54 K, at an energy of 15 meV. The energy ER of the observed spin resonance is broadly consistent with the relationship E_R = 4.9 k_B T_c, but is slightly enhanced compared to the values observed in other Fe-based superconductors. We discuss the nature of the electron pairing symmetry by comparing the value of E_R with that deduced from the total superconducting gap value integrated over the Fermi surface.
