2011/01/31 by D. Nicoletti, D Nicoletti, P Di Pietro +12 · 13 citations
Materials Science · Physics and Astronomy · #Copper-based nanomaterials and applications #Diagram #Doping #Infrared #Iron-based superconductors research #Optical conductivity #Phase diagram #Physics of Superconductivity and Magnetism #Scattering #Scattering rate #Softening #Superconductivity #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1088/1367-2630/13/12/123009
published in New Journal of Physics 13(12), 123009 (IOP Publishing) · 28 pages, 14 figures
arxiv created 2011/10/25 · openalex publication_date 2011/12/06 · arxiv updated 2015/03/17 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/08
The ab -plane optical conductivity of 11 single crystals, belonging to the families Sr 2− x CuO 2 Cl 2 , Y 1− x Ca x Ba 2 Cu 3 O 6 , Bi 2 Sr 2− x La x CuO 6 and Bi 2 Sr 2 CaCu 2 O 8 , has been measured with hole concentrations p between 0 and 0.18 and for 6 K ⩽ T ⩽ 500 K to obtain an infrared picture of the p , T phase diagram of the Cu–O plane. At extreme dilution ( p = 0.005), a narrow peak is observed at 1570 cm −1 (195 meV), which we assign to a single-hole bound state. For increasing doping, that peak broadens into a far-infrared (FIR) band whose low-energy edge sets the insulating gap. The insulator-to-metal transition (IMT) occurs when the softening of the FIR band closes the gap, thus evolving into a Drude term. In the metallic phase, a multi-band analysis identifies a mid-infrared band which weakly depends on temperature and softens for increasing p , while the extended-Drude analysis leads to an optical scattering rate larger than the frequency, as was found in other cuprates. The infrared spectral weight W ( T ) is consistent with a Fermi liquid renormalized by strong correlations, provided that the T 4 term of the Sommerfeld expansion is included above 300 K. In the superconducting phase, the optical response of single-layer Bi 2 Sr 2− x La x CuO 6 at optimum doping is similar to that of the corresponding optimally doped bilayer Bi 2 Sr 2 CaCu 2 O 8 .