Optical properties in the hole-doped Ca8.5Na1.5(Pt3As8)(Fe2As2)5 single crystal

Abstract

For newly synthesized hole-doped Ca8.5Na1.5(Pt3As8)(Fe2As2)5 single crystals, we measured the infrared reflectivity spectrum and the magnetic field dependence of magnetoresistivity and Hall resistivity. The results of these two experiments in normal states are well described by two band models. In normal states below 150 K, the optical conductivity spectrum shows the transfer of spectral weights from the mid-infrared region to the near-infrared region by Hund's coupling, a strong correlation effect. Meanwhile, the carrier concentration evaluated by magnetoresistivity and Hall resistivity decreases significantly at 150 K due to the formation of pseudogap. In the superconducting state, the spectral weight in the low frequency region by the superconducting condensate is completely suppressed, which is well analyzed by the generalized Mattis-Bardeen (M-B) model with a two superconducting gap.

Keywords

• Strong correlation effect
• Hund’s coupling
• High-frequency spectral weight transfer
• Superconducting gap
• Pseudogap
• Hole-doped (Ca1-xNax)10(Pt3As8)(Fe2As2)5