Impact of electron-electron interactions on the thermoelectric efficiency of graphene quantum point contacts

TL;DR

This study explores how electron-electron interactions influence the thermoelectric efficiency of graphene nanoribbons, revealing that many-body effects can enhance efficiency through interference phenomena, with implications for energy-harvesting devices.

Contribution

It demonstrates the significant role of electron-electron interactions in boosting thermoelectric efficiency in graphene nanoribbons using a mean-field approach.

Findings

Electron-electron interactions induce interference effects that enhance thermoelectric efficiency.

Efficiency enhancement occurs in both trivial and topological insulator regimes.

Proposed experimental setup to validate the theoretical predictions.

Abstract

Thermoelectric materials open a way to harness dissipated energy and make electronic devices less energy-demanding. Heat-to-electricity conversion requires materials with a strongly suppressed thermal conductivity but still high electronic conduction. This goal is largely achieved with the help of nanostructured materials, even if the bulk counterpart is not highly efficient. In this work, we investigate how thermoelectric efficiency is enhanced by many-body effects in graphene nanoribbons at low temperature. To this end, starting from the Kane-Mele-Hubbard model within a mean-field approximation, we carry out an extensive numerical study of the impact of electron-electron interactions on the thermoelectric efficiency of graphene nanoribbons with armchair or zigzag edges. We consider two different regimes, namely trivial and topological insulator. We find that electron-electron interactions are crucial for the appearance of interference phenomena that give rise to an enhancement of the thermoelectric efficiency of the nanoribbons. Lastly, we also propose an experimental setup that would help to test the validity of our conclusions.