Abstract
By changing the measurement temperature (T), one can vary the effective sample size so as to study the renormalization group (RG) (or T-driven) flow of a semiconductor, a topological insulator, or a graphene device in the complex conductivity plane. Here we report RG flow of large-area, strongly disordered monolayer graphene epitaxially grown on SiC, which becomes insulating as T decreases for zero magnetic field. We observe cusp-like RG flow towards (σxy = e2/h, σxx = e2/h) where σxy and σxx are Hall conductivity and diagonal conductivity respectively. Such features, indicative of a fixed-temperature phase transition, have never been observed before and cannot be explained by existing RG models based on a modular symmetry group. Therefore, our results suggest the need for new theoretical models and experimental study leading to an understanding of strongly disordered two-dimensional materials such as graphene, few-layer black phosphorus, WSe2, and so on.
Original language | English |
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Pages (from-to) | 31333-31337 |
Number of pages | 5 |
Journal | RSC Advances |
Volume | 7 |
Issue number | 50 |
DOIs | |
State | Published - 1 Jan 2017 |