  We propose a scheme for driving a dimer of spatially separated qubits into a
maximally entangled non-equilibrium steady state. A photon-mediated retarded
interaction between the qubits is realized by coupling them to two
tunnel-coupled leaky cavities where each cavity is driven by a coherent
microwave tone. The proposed cooling mechanism relies on striking the right
balance between the unitary and driven-dissipative dynamics of the qubit
subsystem. We map the dimer to an effective transverse-field XY model coupled
to a non-equilibrium bath that can be suitably engineered through the choice of
drive frequencies and amplitudes. We show that both singlet and triplet states
can be obtained with remarkable fidelities. The proposed protocol can be
implemented with a superconducting circuit architecture that was recently
experimentally realized and paves the way to achieving large-scale entangled
systems that are arbitrarily long lived.

Quantum Physics;Mesoscale and Nanoscale Physics;Quantum Gases