  We studied orientation dependent transport in vicinal N-polar AlGaN/GaN
heterostructures. We observed significant anisotropy in the current carrying
charge parallel and perpendicular to the miscut direction. A quantitative
estimate of the charge anisotropy was made based on gated TLM and Hall
measurements. The formation of electro-statically confined one-dimensional
channels is hypothesized to explain charge anisotropy. A mathematical model was
used to verify that polarization charges distributed on miscut structure can
create lateral one-dimensional confinement in vicinal substrates. This
polarization-engineered electrostatic confinement observed is promising for new
research on low-dimensional physics and devices besides providing a template
for manufacturable one-dimensional devices.
