2007/05/22 by J. L. McChesney, Aaron Bostwick, McChesney, Jessica L. +11 · 1 citation
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Graphene research and applications #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #Superconductivity in MgB2 and Alloys
paper · pdf · doi:10.48550/arxiv.0705.3264
openalex publication_date 2007/05/22 · openalex created_date 2022/10/02 · openalex updated_date 2026/07/28
The nature of the coupling leading to superconductivity in layered materials\nsuch as high-Tc superconductors and graphite intercalation compounds (GICs) is\nstill unresolved. In both systems, interactions of electrons with either\nphonons or other electrons or both have been proposed to explain\nsuperconductivity. In the high-Tc cuprates, the presence of a Van Hove\nsingularity (VHS) in the density of states near the Fermi level was long ago\nproposed to enhance the many-body couplings and therefore may play a role in\nsuperconductivity. Such a singularity can cause an anisotropic variation in the\ncoupling strength, which may partially explain the so-called nodal-antinodal\ndichotomy in the cuprates. Here we show that the topology of the graphene band\nstructure at dopings comparable to the GICs is quite similar to that of the\ncuprates and that the quasiparticle dynamics in graphene have a similar\ndichotomy. Namely, the electron-phonon coupling is highly anisotropic,\ndiverging near a saddle point in the graphene electronic band structure. These\nresults support the important role of the VHS in layered materials and the\npossible optimization of Tc by tuning the VHS with respect to the Fermi level.\n