Electronic structure and properties of superconducting materials with simple Fermi surfaces

Abstract

The electronic structures of the ground state for several different superconducting materials, such as cuprates, conventional 3-dimensional superconductors, doped semiconductors and low-dimensional systems, are quite different and sometimes in contrast to what is supposed to make a superconductor. Properties like the Fermi-surface (FS) topology, density-of-states (DOS), stripes, electron-phonon coupling (${\lambda }_{ep}$) and spin fluctuations (${\lambda }_{sf}$) are analyzed in order to find clues to what might be important for the mechanism of superconductivity. A high DOS at $E_F$ is important for standard estimates of ${\lambda }^{\prime }s$, but it is suggested that superconductivity can survive a low DOS if the FS is simple enough. Superconducting fluctuations are plausible from coupling to long wave length modes in underdoped cuprates, where short coherence length is a probable obstacle for long-range superconductivity. Thermal disorder is recognized as a limiting factor for large $T_C$ independently of doping.

6 pages, 5 figures, proceedings Superstripes 2014 conference Erice

References in corpus (9)

• Three-dimensional MgB${}_2$-type superconductivity in hole-doped diamond
• Origin of Superconductivity in Boron-doped Diamond
• Fermi surface of the most dilute superconductor
• Electron-Phonon Coupling in Boron-Doped Diamond Superconductor
• Metallic State in Cubic FeGe beyond its Quantum Phase Transition
• Enhancement of the superconducting critical temperature of Sr2CuO3+d up to 95K by ordering dopant atoms
• Different doping from apical and planar oxygen vacancies in Ba${}_2$CuO${}_{4-\delta }$ and La${}_2$CuO${}_{4-\delta }$
• Properties of high-T${}_C$ copper oxides from the nearly-free electron model
• Spin-phonon coupling, q-dependence of spin excitations and high-T${}_C$ superconductivity from band models

Cited by in corpus (1)

• Superstripes in the Low Energy Physics of Complex Quantum Matter at the Mesoscale