Superconductivity in graphite-diamond hybrid

TL;DR

This paper predicts a new superconducting graphite-diamond hybrid with a transition temperature around 39-42 K at ambient pressure, highlighting the potential of carbon-based materials for high-temperature superconductivity.

Contribution

First-principles calculations reveal a novel graphite-diamond hybrid with high Tc, supported by recent experimental structural data, advancing the understanding of carbon-based superconductors.

Findings

Predicted Tc of approximately 39 K at ambient pressure.

Strain can increase Tc to about 42 K.

Electron-phonon coupling at the junction is key to superconductivity.

Abstract

Search for new high-temperature superconductors and insight into their superconducting mechanism are of fundamental importance in condensed matter physics. The discovery of near-room temperature superconductivity at more than a million atmospheres ushers in a new era for superconductors. However, the critical task of identifying materials with comparable superconductivity at near or ambient pressure remains. Carbon materials can always lead to intriguing surprises due to their structural diversity and electronic adjustability. Insulating diamond upon doping or external stimuli has achieved superconducting state. Thus, it still has a great opportunity to find superconducting ones with higher transition temperature (Tc). Here, we report an intrinsic superconducting graphite-diamond hybrid through first-principles calculations, whose atomic-resolution structural characteristics have been experimentally determined recently. The predicted Tc is approximated at 39 K at ambient pressure, and strain energizing can further boost Tc to 42 K. The strong electron-phonon coupling associated with the out-of-plane vibration of carbon atoms at the junction plays a dominant role in the superconducting transition. Our work demonstrates the great potential of such carbon materials as high-Tc superconductors, which will definitely attract extensive research.