Quantum Hall Effect in Fractal Graphene: Growth and Properties of Graphlocons

TL;DR

This study reports the synthesis of fractal-shaped dendritic graphene crystals with high electronic quality, exhibiting quantum Hall effects, and investigates their growth mechanisms and transport properties at low temperatures.

Contribution

It introduces a method to grow high-quality fractal graphene crystals with dendritic shapes and characterizes their electronic and quantum Hall properties.

Findings

Dendritic graphene crystals up to 0.25 mm were synthesized.

Quantum Hall oscillations observed above 4 Tesla.

High mobility of up to 6300 cm²V⁻¹s⁻¹ demonstrated.

Abstract

Highly dendritic graphene crystals up to 0.25 mm in diameter are synthesized by low pressure chemical vapor deposition inside a copper enclosure. With their sixfold symmetry and fractal-like shape, the crystals resemble snowflakes. The evolution of the dendritic growth features is investigated for different growth conditions and surface diffusion is found to be the growth-limiting step responsible for the formation of dendrites. The electronic properties of the dendritic crystals are examined down to sub-Kelvin temperatures, showing a mobility of up to 6300 cm$^2$V$^{-1}$s$^{-1}$ and quantum Hall oscillations are observed above 4T. These results demonstrate the high quality of the transport properties despite their rough dendritic edges.