Heating causes non-linear microwave absorption anomaly in single wall carbon nanotubes

TL;DR

This study reveals a slow, non-linear microwave absorption anomaly in single wall carbon nanotubes at low temperatures, primarily caused by heat exchange dynamics rather than intrinsic electronic effects.

Contribution

It introduces a time-resolved microwave impedance measurement method to analyze the slow dynamics of the absorption anomaly in carbon nanotubes.

Findings

Anomaly exhibits extremely slow dynamics lasting hundreds of seconds.

The anomaly is attributed to heat exchange, not intrinsic electronic properties.

Microwave impedance measurements effectively reveal slow thermal processes.

Abstract

Microwave impedance measurements indicate a non-linear absorption anomaly in single wall carbon nanotubes at low temperatures (below $20$ K). We investigate the nature of the anomaly using a time resolved microwave impedance measurement technique. It proves that the anomaly has an extremely slow, a few hundred second long dynamics. This strongly suggests that the anomaly is not caused by an intrinsic electronic effect and that it is rather due to a slow heat exchange between the sample and the environment.