2008/08/31 by J. G. Checkelsky, Joseph G. Checkelsky, Lu Li +2 · 6 citations
Materials Science · Physics and Astronomy · #Graphene research and applications #Quantum and electron transport phenomena #Topological Materials and Phenomena #cond-mat.mes-hall #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.79.115434
published as Phys. Rev. B 79, 115434 (2009) · 7 pages, 9 figures. Slight change in title, 1 new figure (9) and revised text
openalex publication_date 2009/03/24 · arxiv created 2009/03/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We have investigated the behavior of the resistance of graphene at the n=0 Landau level in an intense magnetic field H. Employing a low-dissipation technique (with power P<3 fW), we find that at low temperature T, the resistance at the Dirac point R0(H) undergoes a 1000-fold increase from \ensuremath∼10 k\ensuremathΩ to 40 M\ensuremathΩ within a narrow interval of field. The abruptness of the increase suggests that a transition to an insulating ordered state occurs at the critical field Hc. Results from five samples show that Hc depends systematically on the disorder, as measured by the offset gate voltage V0. Samples with small V0 display a smaller critical field Hc. Empirically, the steep increase in R0 fits accurately a Kosterlitz-Thouless-type correlation length over three decades. The curves of R0 vs T at fixed H approach the thermal-activation form with a gap \ensuremathΔ\ensuremath∼15 K as H\ensuremath→Hc^\ensuremath-, consistent with a field-induced insulating state.