Integer and multiple fractional values of <i>R</i><sub>H</sub> in gateless, millimeter-scale, monolayer epitaxial graphene <i>p-n</i> junctions
ORAL
Abstract
We grew nearly defect-free and monolayer epitaxial graphene (EG) on a hexagonal SiC substrate of centimeter-scale at 18500 C and developed a new technique to fabricate electrostatic-gate-free, monolayer EG devices. These devices were gated by static chemical doping, with designs including p-type and n-type regions in series and in 2x2 checkerboard patterns, using simple ultraviolet photolithography. This technique significantly reduces the device processing time compared to electron beam lithography and resulted in approximately 200 nm wide dissipation-free junctions. We performed the electromagnetic measurements of integer (1, 2, 3, 4, 5, 6, 7, and 8) and fractional (2/3, 8/7, 6/17, 12/13, 24/29, 32/57, and many more) multiples of the quantized Hall resistance in the ν=2 plateau (RH ≈12906 Ω) by applying single and multiple current injection points, respectively. Finally, we modeled all measured experimental data using an LTspice circuit simulator and predicted more complex embodiments of the quantum Hall resistance checkerboard. These simulations highlight the parameter space within which these devices could operate.
*U. S. Department of Commerce "National Research Council’s Research Associateship Program"
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Presenters
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Dinesh Patel
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA