  The use of multiple current terminals on millimeter-scale graphene $p-n$
junction devices fabricated with Corbino geometries, or quantum Hall resistance
dartboards, have enabled the measurement of several fractional multiples of the
quantized Hall resistance at the $\nu=2$ plateau ($R_H\approx 12906 {\Omega}$).
Experimentally obtained values agreed with corresponding numerical simulations
performed with the LTspice circuit simulator. More complicated designs of the
quantum Hall resistance dartboard were simulated to establish the potential
parameter space within which these Corbino-type devices could output
resistance. Most importantly, these measurements support simpler processes of
ultraviolet lithography as a more efficient means of scaling up graphene-based
device sizes while maintaining sufficiently narrow junctions.
