Towards room-temperature superconductivity in low-dimensional C60 nanoarrays: An ab initio study

TL;DR

This study explores how low-dimensional arrangements of doped C60 molecules can enhance the density of states at the Fermi level, potentially leading to room-temperature superconductivity through increased electron-phonon coupling.

Contribution

It introduces a theoretical approach to increase the critical temperature of superconductivity in doped C60 by manipulating their dimensional arrangements and electronic properties.

Findings

2D C60 arrays show increased N(E_F) with decreased bandwidth.

Quasi-1D C60 arrangements may achieve near room-temperature T_c.

Doped C60 in nanotube bundles or diluted 3D crystals are promising structures.

Abstract

We propose to raise the critical temperature $T_c$ for superconductivity in doped C$_{60}$ molecular crystals by increasing the electronic density of states at the Fermi level $N(E_F)$ and thus the electron-phonon coupling constant in low-dimensional C$_{60}$ nanoarrays. We consider both electron and hole doping and present numerical results for $N(E_F)$, which increases with decreasing bandwidth of the partly filled $h_u$ and $t_{1u}$ derived frontier bands with decreasing coordination number of C$_{60}$. Whereas a significant increase of $N(E_F)$ occurs in 2D arrays of doped C$_{60}$ intercalated in-between graphene layers, we propose that the highest $T_c$ values approaching room temperature may occur in bundles of nanotubes filled by 1D arrays of externally doped C$_{60}$ or La@C$_{60}$, or in diluted 3D crystals, where quasi-1D arrangements of C$_{60}$ form percolation paths.