2005/12/31 by Keiji Yada, Hiroshi Kontani · 24 citations
Materials Science · Physics and Astronomy · #Advanced Thermoelectric Materials and Devices #Angle-resolved photoemission spectroscopy #Condensed matter physics #Electron #Electronic structure #Kondo effect #Magnetic and transport properties of perovskites and related materials #Phonon #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Superconductivity #Valence (chemistry) #cond-mat.supr-con
paper · pdf · doi:10.1143/jpsj.75.033705
published in Journal of the Physical Society of Japan 75(3), 033705 (Physical Society of Japan) · 5 pages, 4 figures; v2:Added references, published in J. Phys. Soc. Jpn
openalex publication_date 2006/03/14 · arxiv created 2006/03/22 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/08
To study the possible mechanism of superconductivity in Na0.35CoO2, we examine the interaction between all the relevant optical phonons (breathing and shear phonons) and t2g(a1g+eg')-electrons of Co-ions, and study the transition temperature for a s-wave superconductivity. The obtained T\rm c is very low when the eg'-valence-bands are far below the Fermi level. However, T\rm c is strongly enhanced when the top of the eg'-valence-bands is close to the Fermi level (say -50meV), thanks to interband hopping of Cooper pairs caused by shear phonons. This ``valence-band Suhl-Kondo mechanism'' due to shear phonons is significant to understand the superconductivity in Na0.35CoO2. By the same mechanism, the kink structure of the band-dispersion observed by ARPES, which indicates the strong mass-enhancement (m^∗/m∼3) due to optical phonons, is also explained.