About Two-Component Physics of HTSC

• Published in: Journal of superconductivity and novel magnetism Vol. 22; no. 2; pp. 155 - 163
• Main Authors: Kusmartsev, F. V., Saarela, Mikko
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Boston Springer US 01.02.2009; Springer
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure; Exact sciences and technology; Magnetic Materials; Magnetism; Original Paper; Physics; Physics and Astronomy; Properties of type I and type II superconductors; Strongly Correlated Systems; Superconductivity; First principles calculation; Pseudogap; Superconductor-insulator; Interaction; Superconductivity; Electronic phase separation; Bose fluid; Co-existence; Localised states; HTSC; Cuprates; Coulomb; Localized states; Ground states; Doping; Charge density waves; High-Tc superconductors; Attraction interaction; Cuprates Coulomb; Superconducting energy gap; Coulomb interaction; Quasiparticles; Impurities; Superconductor- insulator; Density functional method; Instability; Carrier density
• ISSN: 1557-1939; 1557-1947
• DOI: 10.1007/s10948-008-0396-y

We present a first-principles, microscopic calculation of the ground state of cuprates indicating the presence of two groups of charge carriers in these compounds associated with free and localized states. The localized component arises due to a charge density wave instability in the free component. The instability occurs in underdoped cuprates where the attractive Coulomb interaction between dopant impurities and charge carriers becomes strongly over-screened at low carrier densities and divides charge carriers into two orthogonal states. Within this new two-component state a novel quasi-particle entity, a microscopic Coulomb clump (CC), emerges. Our results are completely consistent with the analysis of the Hall effect and the ARPES spectra made earlier by Gorkov and Teitelbaum (GT) (Phys. Rev. Lett., 97:247003, 2006 , and J. Phys.: Conf. Ser., 108:012009, 2008 ) that includes also available neutron scattering, NMR and μSR data. The density of localized component is temperature dependent, which is due to thermal activation of bound holes from Coulomb clumps. The clumps also induce nanoscale superstructures observed in Scanning Tunneling Microscope (STM) experiments (Pan, et al. Nature, 413:282–285, 2001 ; Dubi, et al. Nature, 449:876–879, 2007 ; Gomes, et al. Nature, 447:569, 2007 ; Lee, et al. Nature, 442:546, 2006 ; McElroy, et al. Science, 309:1048, 2005 ; Zhu, et al. Phys. Rev. Lett., 97:177001, 2006 ) and are responsible for the pseudogap and Nernst effect in HTSC. Following GT we stress the importance of these findings for the pseudogap physics. We present a first-principles, microscopic calculation of the ground state of cuprates indicating the presence of two groups of charge carriers in these compounds associated with free and localized states. The localized component arises due to a charge density wave instability in the free component. The instability occurs in underdoped cuprates where the attractive Coulomb interaction between dopant impurities and charge carriers becomes strongly over-screened at low carrier densities and divides charge carriers into two orthogonal states. Within this new two-component state a novel quasi-particle entity, a microscopic Coulomb clump (CC), emerges.