Charge-Density-Wave Proximity Effects in Graphene

TL;DR

This study explores how charge density wave phases in TMDCs influence the electronic transport properties of graphene, revealing potential for novel device applications through heterostructure engineering.

Contribution

It introduces the integration of CDW properties of TMDCs into graphene's electronic transport, demonstrating anomalous behaviors during phase transitions for the first time.

Findings

CDW phases induce correlated disorder affecting graphene's transport

Resistivity decreases and mobility increases during CDW transitions

Heterostructures enable control over electronic properties for device applications

Abstract

Certain layered transition metal dichalcogenides (TMDCs), such as 1T-TaS2, show a rich collection of charge density wave (CDW) phases at different temperatures, and their atomic structures and electron conductions have been widely studied. However, the properties of CDW systems that are integrated with other electronic materials have not yet been investigated. Here, we incorporate the CDW properties of TMDCs into the electronic transport of graphene for the first time. During CDW phase transitions, anomalous transport behaviors that are closely related to the formation of correlated disorder in TMDCs were observed in the graphene sample used in this study. In particular, the commensurate CDW phase forms a periodic charge distribution with potential fluctuations, and thus constitutes correlated charged impurities, which decreases resistivity and enhances carrier mobility in graphene. The CDW-graphene heterostructure system demonstrated here paves the way to controlling the temperature-dependent carrier mobility and resistivity of graphene and to developing novel functional electronic devices such as graphene-based sensors and memory devices.