Charge carriers in a graphene sheet, a single layer of graphite, exhibit much distinctive characteristics to those in other two-dimensional electronic systems because of their chiral nature. In this report, we focus on the observation of weak localization in a graphene sheet exfoliated from a piece of natural graphite and nano-patterned into a Hall-bar geometry. Much stronger chiral-symmetry-breaking elastic intervalley scattering in our graphene sheet restores the conventional weak localization. The resulting carrier-density and temperature dependence of the phase coherence length reveal that the electron-electron interaction including a direct Coulomb interaction is the main inelastic scattering factor while electron-hole puddles enhance the inelastic scattering near the Dirac point.
@article{arxiv.0808.2599,
title = {Inelastic scattering in a monolayer graphene sheet; a weak-localization study},
author = {Dong-Keun Ki and Dongchan Jeong and Jae-Hyun Choi and Kee-Su Park and Hu-Jong Lee},
journal= {arXiv preprint arXiv:0808.2599},
year = {2012}
}