2015/02/28 by Andrzej Ptok, Konrad Jerzy Kapcia
Materials Science · Physics and Astronomy · #Coherence (philosophical gambling strategy) #Homogeneous #Homogeneous space #Impurity #Iron-based superconductors research #Organic and Molecular Conductors Research #Pairing #Physics of Superconductivity and Magnetism #Quantum tunnelling #Scanning tunneling microscope #Superconductivity #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1088/0953-2048/28/4/045022
published as Supercond. Sci. Technol. 28, 045022 (2015) · 11 pages, 4 figures
openalex publication_date 2015/03/13 · arxiv created 2015/03/14 · arxiv updated 2015/03/17 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The effects of a single non-magnetic impurity on superconducting states in the Penson–Kolb–Hubbard model have been analyzed. The investigations have been performed within the Hartree–Fock mean field approximation in two steps: (i) the homogeneous system is analysed using the Bogoliubov transformation, whereas (ii) the inhomogeneous system is investigated by self-consistent Bogoliubov-de Gennes equations (with the exact diagonalization and the kernel polynomial method). We analysed both signs of the pair hopping, which correspond to s -wave and η -wave superconductivity. Our results show that an enhancement of the local superconducting gap at the impurity-site occurs for both cases. We obtained that Cooper pairs are scattered (at the impurity site) into the states which are from the neighborhoods of the states, which are commensurate ones with the crystal lattice. Additionally, in the η -phase there are peaks in the local-energy gap (in momentum space), which are connected with long-range oscillations in the spatial distribution of the energy gap, superconducting order parameter (SOP), as well as effective pairing potential. Our results can be contrasted with the experiment and predicts how to experimentally differentiate these two different symmetries of SOP by the scanning tunneling microscopy technique.