Related papers: Quantized Transport in Graphene p-n Junctions in M…
We have developed a device fabrication process to pattern graphene into nanostructures of arbitrary shape and control their electronic properties using local electrostatic gates. Electronic transport measurements have been used to…
The quantum Hall effect in graphene p-n junctions is studied numerically with emphasis on the effect of disorder at the interface of two adjacent regions. Conductance plateaus are found to be attached to the intensity of the disorder, and…
We report on the fabrication and transport studies of a single-layer graphene p-n junction. Carrier type and density in two adjacent regions are individually controlled by electrostatic gating using a local top gate and a global back gate.…
We study the effect of local modulation of charge density and carrier type in graphene field effect transistors using a double top gate geometry. The two top gates lead to the formation of multiple \emph{p-n} junctions. Electron transport…
We investigate electronic transport through a graphene $n$-$p$ junction in the quantum Hall effect regime at high perpendicular magnetic field, when the filling factors in the $n$-doped and $p$-doped regions are fixed to 2 and -2…
We report simultaneous transport and scanning microwave impedance microscopy to examine the correlation between transport quantization and filling of the bulk Landau levels in the quantum Hall regime in gated graphene devices. Surprisingly,…
The quantum Hall effect is a remarkable manifestation of quantized transport in a two-dimensional electron gas. Given its technological relevance, it is important to understand its development in realistic nanoscale devices. In this work we…
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…
At high magnetic fields the conductance of graphene is governed by the half-integer quantum Hall effect. By local electrostatic gating a \textit{p-n} junction perpendicular to the graphene edges can be formed, along which quantum Hall…
Low temperature magnetoconductance measurements were made in the vicinity of the charge neutrality point. Two origins for the fluctuations were identified close to the CNP. At very low magnetic fields there exist only mesoscopic…
Strongly correlated electron liquids which occur in quantizing magnetic fields reveal a cornucopia of fascinating quantum phenomena such as fractionally charged quasiparticles, anyonic statistics, topological order, and many others. Probing…
Owing to a linear and gapless band structure and a tunability of the charge carrier type, graphene offers a unique system to investigate transport of Dirac Fermions at p-n junctions (PNJs). In a magnetic field, combination of quantum Hall…
Low-energy transport measurements in Quantum Hall systems have been argued to be governed by emergent modular symmetries whose predictions are robust against many of the detailed microscopic dynamics. We propose the recently-observed…
When electrons are confined in two-dimensional (2D) materials, quantum mechanically enhanced transport phenomena, as exemplified by the quantum Hall effects (QHE), can be observed. Graphene, an isolated single atomic layer of graphite, is…
We report an observation of conductance fuctuations (CFs) in the bipolar regime of quantum hall (QH) plateaus in graphene (p-n-p/n-p-n) devices. The CFs in the bipolar regime are shown to decrease with increasing bias and temperature. At…
We investigate transport in a gate-defined graphene quantum point contact in the quantum Hall regime. Edge states confined to the interface of p and n regions in the graphene sheet are controllably brought together from opposite sides of…
Using high quality graphene pnp junctions, we observe prominent conductance fluctuations on transitions between quantum Hall (QH) plateaus as the top gate voltage Vtg is varied. In the Vtg-B plane, the fluctuations form crisscrossing lines…
We present temperature-dependent magneto-transport experiments around the charge neutrality point in graphene and determine the amplitude of potential fluctuations $s$ responsible for the formation of electron-hole puddles. The experimental…
A yet unexplored area in graphene electronics is the field of quantum ballistic transport through graphene nanostructures. Recent developments in the preparation of high mobility graphene are expected to lead to the experimental…
The formation of quantum Hall channels inside the bulk of graphene is studied using various contact and gate geometries. p-n junctions are created along the longitudinal direction of samples, and enhanced conductance is observed in the case…