  We propose and analyze a setup based on (solid-state) qubits coupled to a
common multi-mode transmission line, which allows for coherent spin-spin
interactions over macroscopic on-chip distances, without any ground-state
cooling requirements for the data bus. Our approach allows for the realization
of fast deterministic quantum gates between distant qubits, the simulation of
quantum spin models with engineered (long-range) interactions, and provides a
flexible architecture for the implementation of quantum approximate
optimization algorithms.
