  Systems of photonic crystal cavities coupled to quantum dots are a promising
architecture for quantum networking and quantum simulators. The ability to
independently tune the frequencies of laterally separated quantum dots is a
crucial component of such a scheme. Here, we demonstrate independent tuning of
laterally separated quantum dots in photonic crystal cavities coupled by
in-plane waveguides by implanting lines of protons which serve to electrically
isolate different sections of a diode structure.
