Observation of quantum Hall plateau-plateau transition and scaling behavior of the zeroth Landau level in graphene p-n-p junctions

Abstract

We report distinctive magnetotransport properties of a graphene p-n-p junction prepared by controlled diffusion of metallic contacts. In most cases, materials deposited on a graphene surface introduce substantial carrier scattering, which greatly reduces the high mobility of intrinsic graphene. However, we show that an oxide layer only weakly perturbs the carrier transport, which enables fabrication of a high-quality graphene p-n-p junction through a one-step and resist-free method. The measured conductance-gate voltage $(G-V_G)$ curves can be well described by a metal contact model, which confirms the charge density depinning due to the oxide layer. The graphene p-n-p junction samples exhibit pronounced quantum Hall effect, a well-defined transition point of the zeroth Landau level (LL), and scaling behavior. The scaling exponent obtained from the evolution of the zeroth LL width as a function of temperature exhibits a relatively low value of $\kappa =0.21\pm 0.01$. Moreover, we calculate the energy level for the LLs based on the distribution of plateau-plateau transition points, further validating the assignment of the LL index of the QH plateau-plateau transition.

References in corpus (17)

• The electronic properties of graphene
• Chiral tunneling and the Klein paradox in graphene
• Room-Temperature Quantum Hall Effect in Graphene
• Unconventional quantum Hall effect and Berry's phase of 2pi in bilayer graphene
• Quantum interference and Klein tunneling in graphene heterojunctions
• Strong suppression of weak (anti)localization in graphene
• Electronic transport and quantum Hall effect in bipolar graphene p-n-p junction
• Evidence of the role of contacts on the observed electron-hole asymmetry in graphene
• Klein Backscattering and Fabry-Perot Interference in Graphene Heterojunctions
• Quantized Transport in Graphene p-n Junctions in Magnetic Field
• Phase analysis of quantum oscillations in graphite
• Charge Transport and Inhomogeneity near the Charge Neutrality Point in Graphene
• Charge-density depinning at metal contacts of graphene field-effect transistors
• Splitting of the Zero-Energy Landau Level and Universal Dissipative Conductivity at Critical Points in Disordered Graphene
• Metallic and Insulating Adsorbates on Graphene
• Path of the current flow at the metal contacts of graphene field-effect transistors with distorted transfer characteristics
• Magneto-transport of graphene and quantum phase transitions in the quantum Hall regime

Cited by in corpus (1)

• Chiral interface states in graphene $p$-$n$ junctions