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Related papers: Superconductivity in C6Ca

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The field of superconductivity in the class of materials known as graphite intercalation compounds has a history dating back to the 1960s. This paper recontextualizes the field in light of the discovery of superconductivity in CaC6 and YbC6…

Monolayer graphene exhibits many spectacular electronic properties, with superconductivity being arguably the most notable exception. It was theoretically proposed that superconductivity might be induced by enhancing the electron-phonon…

We have obtained bulk samples of the graphite intercalation compound, CaC6, by a novel method of synthesis from highly oriented pyrolytic graphite. The crystal structure has been completely determined showing that it is the only member of…

Materials Science · Physics 2009-11-11 N. Emery , C. Herold , M. d Astuto , V. Garcia , Ch. Bellin , J. F. Mareche , P. Lagrange , G. Loupias

Point-contact tunneling on CaC$_6$ crystals reproducibly reveals superconducting gaps, $\Delta$, of 2.3$\pm$0.2 meV which are $\sim$~40% larger than earlier reports. That puts CaC$_6$ into the class of very strong-coupled superconductors…

Superconductivity · Physics 2008-03-05 C. Kurter , L. Ozyuzer , Daniel Mazur , J. F. Zasadzinski , D. Rosenmann , H. Claus , D. G. Hinks , K. E. Gray

We present the results of a neutron scattering study of the high energy phonons in the superconducting graphite intercalation compound CaC$_6$. The study was designed to address hitherto unexplored aspects of the lattice dynamics in…

Ca-intercalation has opened a way for superconductivity in graphene on SiC. However, the atomic and electronic structures being critical for superconductivity are still under discussion. We find the essential role of the interface between…

Insight into why superconductivity in pristine and doped monolayer graphene seems strongly suppressed has been central for the recent years' various creative approaches to realize superconductivity in graphene and graphene-like systems. We…

Superconductivity · Physics 2020-06-12 Even Thingstad , Akashdeep Kamra , Justin W. Wells , Asle Sudbø

In this letter, we report the discovery of superconductivity in Li3Ca2C6. Several graphite intercalation compounds (GICs) with electron donors, are well known as superconductors. It is probably not astonishing, since it is generally…

The quasiparticle relaxation dynamics of the iron-based superconductor CsCa$_2$Fe$_4$As$_4$F$_2$ ($T_c$ $\sim$ 29 K) were investigated using ultrafast optical spectroscopy. A pseudogap ($\Delta_{PG}$ $\approx$ 3.3 meV) was observed to open…

Graphene, a zero-gap semimetal, can be transformed into a metallic, semiconducting or insulating state by either physical or chemical modification. Superconductivity is conspicuously missing among these states despite considerable…

Superconductivity · Physics 2016-04-05 J. Chapman , Y. Su , C. A. Howard , D. Kundys , A. Grigorenko , F. Guinea , A. K. Geim , I. V. Grigorieva , R. R. Nair

Using density functional theory we investigate the occurrence of superconductivity in AC$_6$ with A=Mg,Ca,Sr,Ba. We predict that at zero pressure, Ba and Sr should be superconducting with critical temperatures (T$_c$) 0.2 K and 3.0 K,…

Superconductivity · Physics 2009-11-11 Matteo Calandra , Francesco Mauri

The low energy phonons of two different graphite intercalation compounds (GICs) have been measured as a function of temperature using inelastic x-ray scattering (IXS). In the case of the non-superconductor BaC6, the phonons observed are…

The nature of the coupling leading to superconductivity in layered materials such as high-Tc superconductors and graphite intercalation compounds (GICs) is still unresolved. In both systems, interactions of electrons with either phonons or…

Strongly Correlated Electrons · Physics 2007-05-24 Jessica L. McChesney , Aaron Bostwick , Taisuke Ohta , Konstantin V. Emtsev , Thomas Seyller , Karsten Horn , Eli Rotenberg

The discovery of superconductivity in CaC6 with a critical temperature (Tc) of 11.5 K reignites much interest in exploring high-temperature superconductivity in graphite intercalation compounds (GICs). Here we identify a GIC NaC4,…

We study the graphite intercalated compound CaC$_6$ by means of Eliashberg theory, focusing on the anisotropy properties. An analysis of the electron-phonon coupling is performed, and we define a minimal 6-band anisotropy structure.…

Superconductivity · Physics 2012-05-15 A. Sanna , S. Pittalis , J. K. Dewhurst , M. Monni , S. Sharma , G. Ummarino , S. Massidda , E. K. U. Gross

We have investigated the atomic structure of superconducting Ca-intercalated bilayer graphene on a SiC(0001) substrate using total-reflection high-energy positron diffraction. By comparing the experimental rocking-curves with ones…

Materials Science · Physics 2019-11-20 Y. Endo , Y. Fukaya , I. Mochizuki , A. Takayama , T. Hyodo , S. Hasegawa

Lortz et al. [Phys. Rev. B 73, 024512 (2006)] have utilized specific heat and resistivity measurements as "thermal spectroscopies" to deconvolve the spectrum of the electron-phonon interaction in YB$_6$ assuming a major role of the low…

Superconductivity · Physics 2013-04-01 P. Szabo , J. Girovsky , Z. Pribulova , J. Kacmarcik , T. Mori , P. Samuely

Electrons in isolated graphene layers are a two-dimensional gas of massless Dirac Fermions. In realistic devices, however, the electronic properties are modified by elastic deformations, interlayer coupling and substrate interaction. Here…

We present a theoretical investigation on electron-phonon superconductivity of honeycomb MX$_2$ layered structures. Where X is one element of the group-IV (C, Si or Ge) and M an alkali or an alkaline-earth metal. Among the studied…

Superconductivity · Physics 2015-06-23 José A. Flores-Livas , Antonio Sanna

We discuss the possibility of superconductivity in graphene taking into account both electron-phonon and electron-electron Coulomb interactions. The analysis is carried out assuming that the Fermi energy is far away from the Dirac points,…

Superconductivity · Physics 2011-12-13 M. Einenkel , K. B. Efetov