• 文献标题:   Cooper pair distribution function of misaligned graphene sheets and determination of superconducting properties
  • 文献类型:   Article
  • 作  者:   GONZALEZPEDREROS GI, PAEZSIERRA BA, BAQUERO R
  • 作者关键词:   cooperpair distribution function, graphene, superconductivity, critical temperature, functional derivative
  • 出版物名称:   DIAMOND RELATED MATERIALS
  • ISSN:   0925-9635 EI 1879-0062
  • 通讯作者地址:   Univ Militar Nueva Granada
  • 被引频次:   2
  • DOI:   10.1016/j.diamond.2019.04.004
  • 出版年:   2019

▎ 摘  要

We report a novel determination of the Copper-pair distribution function Dcp(ta,Ta involving vibrational energy (omega) and critical temperature (T-c). This distribution establishes energy vibrational interval where the Cooper pairs arise. Based on experimental superconductivity for a bilayer graphene twisted at small angles of 1.05 degrees and 1.16 degrees and critical temperatures of 1.7 K and 0.5 K respectively, recently reported elsewhere, we estimated D-cp(omega,T-c) for the same graphene configuration by calculating the Eliashberg function, electronic density and the vibrational density from ab initio calculations. The phonon fingerprint distribution with energy between 0.0 meV and 0.6 meV contributes to the superconductivity, while the Eliashberg functions show a correlation with the critical temperature in this interval. Based on the Functional Derivative Method (FDM), critical temperatures of 1.7 K (1.05 degrees) and 1.71 K (1.16 degrees) are found. Since no experimental data for intermediate angles has been reported, the critical temperature for 1.10 was determined around 1.68 K. The theoretical reason why all computed critical temperatures are very similar is that the Eliashberg function profile has minor changes for the three angles in all the spectral range, and therefore the critical temperatures have minor changes.