Observation of a neutron spin resonance in the bilayered superconductor CsCa2Fe4As4F2

Autor: Adroja, D. T., Blundell, S. J., Lang, F., Luo, H., Wang, Z. -C., Cao, G. -H.
Rok vydání: 2020
Předmět:
Zdroj: J. Phys.: Condens. Matter 32,435603 (2020)
Druh dokumentu: Working Paper
DOI: 10.1088/1361-648X/aba28f
Popis: 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.
Comment: 6 pages, 5 figures
Databáze: arXiv