  The fundamental condition for operating a superlattice (SL) as a Bloch
oscillator is a homogeneous electric field alignment under large applied bias.
This can be done by combining the nonlinear miniband transport channel with a
parallel shunt channel, connected through lateral transport. We report here
about the first realization of such a SL-shunt system. With the
cleaved-edge-overgrowth (CEO) method we combine an undoped superlattice, which
acts as the shunt, with a two-dimensional (2D) cleaved-edge surface
superlattice channel. Our results confirm the long predicted
current-voltage-characteristic (I-V) of a SL in a homogeneous DC electric
field. Excitation experiments in the GHz regime show that our shunt approach
also works in the presence of an external AC electric field.
