Thermal transport mapping in twisted double bilayer graphene

TL;DR

This study uses scanning thermal microscopy to map local thermal properties of twisted double bilayer graphene, revealing increased thermal resistance due to twisting, which advances understanding of thermal transport in 2D moiré materials.

Contribution

It provides the first experimental thermal transport measurements in twisted double bilayer graphene, combining SThM with analytical modeling to elucidate twist-induced thermal resistance changes.

Findings

Thermal resistance increases by approximately 0.3 x 10^6 KW^{-1} in twisted structures.

Twisting alters intrinsic thermal conductivity and tip-sample interface properties.

Results support the potential for thermal engineering in twistronic devices.

Abstract

Two-dimensional (2D) materials have attracted significant interest due to their tunable physical properties when stacked into homo- and hetero-structures. Twisting adjacent layers introduces moir\'{e} patterns that strongly influence the material electronic and thermal behavior. In twisted graphene systems, the twist angle critically alters phonon transport, leading to reduced thermal conductivity compared to Bernal-stacked configurations. However, experimental investigations into thermal transport in twisted structures remain limited. Here, we study the local thermal properties of twisted double bilayer graphene (TDBG) using Scanning Thermal Microscopy (SThM). We find an increase in thermal resistance of $0.3 \pm 0.1 \times 10^6 KW^{-1}$ compared to untwisted bilayers, attributed to changes in both intrinsic thermal conductivity and the tip-sample interface. These results, supported by analytical modeling, provide new insight into thermal transport mechanisms in twisted 2D systems and offer a pathway toward thermal engineering in twistronic devices.