  The electronic states in a corner-overgrown bent GaAs/AlGaAs quantum well
heterostructure are studied with numerical Hartree simulations. Transmission
electron microscope pictures of the junction justify the sharp-corner
assumption. In a tilted magnetic field both facets of the bent quantum well are
brought to a quantum Hall (QH) state, and the corner hosts an unconventional
hybrid system of two coupled counter-propagating quantum Hall edges and an
additional one-dimensional accumulation wire. A subsystems model is introduced,
whereby the total hybrid dispersion and wavefunctions are explained in terms of
the constituent QH edge- and accumulation wire-subsystem dispersions and
wavefunctions. At low magnetic fields, orthonormal basis wavefunctions of the
hybrid system can be accurately estimated by projecting out the lowest bound
state of the accumulation wire from the edge state wavefunctions. At high
magnetic fields, the coupling between the three subsystems increases as a
function of the applied magnetic field, in contrast to coplanar
barrier-junctions of QH systems, leading to large anticrossing gaps between the
subsystem dispersions. These results are discussed in terms of previously
reported experimental data on bent quantum Hall systems.
