Abstract
We fabricate and investigate high-quality graphene devices with contactless, suspended top gates and demonstrate the formation of graphene pnp junctions with tunable polarity and doping levels. The device resistance displays distinct oscillations in the npn regime, arising from the Fabry–Perot interference of holes between the two pn interfaces. At high magnetic fields, we observe well-defined quantum Hall plateaus, which can be satisfactorily fit to theoretical calculations based on the aspect ratio of the device.
Highlights
Home Search Collections Journals About Contact us My IOPscienceThis article has been downloaded from IOPscience. Please scroll down to see the full text article. 2009 New J
We report fabrication of high-quality pnp junctions using suspended, contactless top gates
Using a recently available theory for rectangular device geometry [20], we can satisfactorily account for the two-terminal device conductance at uniform charge densities
Summary
This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2009 New J. The suspended gates can be fabricated at nonzero angles with respect to the source– drain electrodes (figures 1(c) and (d)), by careful control of the direction of metal evaporations Such graphene devices with angled top gates were first proposed in [15], as an experimental platform to observe Klein tunneling, in which the transmission coefficient of charges across high potential barriers strongly depends on the incident angle. The horizontal band of n1 = 0, together with the cyan diagonal line of n2 = 0, partition the data in figure 3(a) into four regions, with different doping combinations, demonstrating a graphene pnp junction with in situ tunable polarity and doping levels. The line represents a linear fit to of n2. (d) the data
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
