  Spin waves and their quanta magnons open up a promising branch of high-speed
and low-power information processing. Several important milestones were
achieved recently in the realization of separate magnonic data processing units
including logic gates, a magnon transistor and units for non-Boolean computing.
Nevertheless, the realization of an integrated magnonic circuit consisting of
at least two logic gates and suitable for further integration is still an
unresolved challenge. Here we demonstrate such an integrated circuit
numerically on the example of a magnonic half-adder. Its key element is a
nonlinear directional coupler serving as combined XOR and AND logic gate that
utilizes the dependence of the spin wave dispersion on its amplitude. The
circuit constitutes of only three planar nano-waveguides and processes all
information within the magnon domain. Benchmarking of the proposed device is
performed showing the potential for sub-aJ energy consumption per operation.
