Impossibility of Increasing N$\acute{\textrm{e}}$el Temperature in Zigzag Graphene Nanoribbon by Electric Field and Carrier Doping

TL;DR

This study demonstrates that applying electric fields and doping in zigzag graphene nanoribbons cannot increase their Néel temperature, as these factors actually decrease it, based on mean-field calculations of magnon energies.

Contribution

The paper introduces a computational approach using the generalized Bloch theorem to efficiently analyze the Néel temperature dependence on electric field and doping.

Findings

Néel temperature decreases with increasing electric field.

Doping also reduces the Néel temperature.

Electric field and doping do not enhance magnetic ordering.

Abstract

We investigated the dependence of N$\acute{\textrm{e}}$el temperature as a critical temperature on the electric field and hole-electron doping in the antiferromagnetically ordered zigzag graphene nanoribbon. The temperature was calculated by averaging the magnon energy in the Brillouin zone within the mean-field approximation. We employed the generalized Bloch theorem instead of the supercell approach to reduce the computational cost significantly to obtain the magnon spectrum. We showed that the N$\acute{\textrm{e}}$el temperature reduces when increasing both the electric field and the hole-electron doping, thus these treatments will never enhance the N$\acute{\textrm{e}}$el temperature.