  The quantum circuit model allows gates between any pair of qubits yet
physical instantiations allow only limited interactions. We address this
problem by providing an interaction graph together with an efficient method for
compiling quantum circuits so that gates are applied only locally. The graph
requires each qubit to interact with 4 other qubits and yet the time-overhead
for implementing any n-qubit quantum circuit is 6 log n. Building a network of
quantum computing nodes according to this graph enables the network to emulate
a single monolithic device with minimal overhead.
