Exotic s-wave superconductivity in alkali-doped fullerides.
TL;DR: In this article, the electron-phonon coupling and electron-electron interactions are used to realize an unconventional s-wave superconductivity in the alkali-doped fullerides.
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Abstract: Alkali-doped fullerides (A3C60 with A = K, Rb, Cs) show a surprising phase diagram, in which a high transition-temperature (Tc) s-wave superconducting state emerges next to a Mott insulating phase as a function of the lattice spacing. This is in contrast with the common belief that Mott physics and phonon-driven s-wave superconductivity are incompatible, raising a fundamental question on the mechanism of the high-Tc superconductivity. This article reviews recent ab initio calculations, which have succeeded in reproducing comprehensively the experimental phase diagram with high accuracy and elucidated an unusual cooperation between the electron-phonon coupling and the electron-electron interactions leading to Mott localization to realize an unconventional s-wave superconductivity in the alkali-doped fullerides. A driving force behind the exotic physics is unusual intramolecular interactions, characterized by the coexistence of a strongly repulsive Coulomb interaction and a small effectively negative exchange interaction. This is realized by a subtle energy balance between the coupling with the Jahn-Teller phonons and Hund's coupling within the C60 molecule. The unusual form of the interaction leads to a formation of pairs of up- and down-spin electrons on the molecules, which enables the s-wave pairing. The emergent superconductivity crucially relies on the presence of the Jahn-Teller phonons, but surprisingly benefits from the strong correlations because the correlations suppress the kinetic energy of the electrons and help the formation of the electron pairs, in agreement with previous model calculations. This confirms that the alkali-doped fullerides are a new type of unconventional superconductors, where the unusual synergy between the phonons and Coulomb interactions drives the high-Tc superconductivity.
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References
Phonon dispersions: Performance of the generalized gradient approximation
Fabio Favot,Andrea Dal Corso +1 more
TL;DR: In this paper, the authors compared the performance of the local density approximation (LDA) with that of the generalized gradient approximations (GGA's!) in the form recently proposed by Perdew, Burke, and Ernzerhof.
Intermolecular overlap geometry gives two classes of fulleride superconductor: electronic structure of 38 K Tc Cs3C60.
George R. Darling,Alexey Y. Ganin,Matthew J. Rosseinsky,Yasuhiro Takabayashi,Kosmas Prassides +4 more
TL;DR: It is found that, despite its smaller packing density, the bcc-derived A15 phase has both a substantially wider bandwidth for the partially occupied t1u band and a higher density of states at the Fermi level.
Structure of Rb:C60 compounds.
Peter W. Stephens,Laszlo Mihaly,John B. Wiley,S.-M. Huang,Richard B. Kaner,François Diederich,Robert L. Whetten,Karoly Holczer +7 more
TL;DR: In this paper, x-ray-diffraction studies on a set of stochastic compounds with nominal composition ranging from 1.5 to 6 were carried out and the corresponding face-centered cubic, body-centered tetragonal, and bodycentered cubic structures were refined.
Low-moment antiferromagnetic ordering in triply charged cubic fullerides close to the metal-insulator transition
Peter Jeglič,Denis Arčon,Denis Arčon,Anton Potočnik,Alexey Y. Ganin,Yasuhiro Takabayashi,Matthew J. Rosseinsky,Kosmas Prassides +7 more
TL;DR: In this article, the authors report on the ambient pressure and spin-lattice relaxation rates of disorder-free A15-structured structures, which shows non-BCS superconductivity at 38 K under pressure.
Electron-phonon coupling strength and implications for superconductivity in alkali-metal-doped fullerenes.
Radi A. Jishi,M. S. Dresselhaus +1 more
TL;DR: The curvature of ${\mathrm{C}}_{60}$ makes it possible for electrons to couple with the low-frequency radial modes and causes the value of the dimensionless electron-phonon coupling parameter, \ensuremath{\lambda}, to be reasonably large.