  The realization of integrated quantum circuits requires precise on-chip
control of charge carriers. Aiming at the coherent coupling of distant
nanostructures at zero magnetic field, here we study the ballistic electron
transport through two quantum point contacts (QPCs) in series in a three
terminal configuration. We enhance the coupling between the QPCs by
electrostatic focusing using a field effect lens. To study the emission and
collection properties of QPCs in detail we combine the electrostatic focusing
with magnetic deflection. Comparing our measurements with quantum mechanical
and classical calculations we demonstrate how the coherent and ballistic
dynamics depend on the details of the QPC confinement potentials.
