Implementing universal quantum gates in coupled cavities

We study a linear array of coupled cavities interacting with two level systems and show how to construct individually addressable qubits in this system from the long-lived atom-photon excitations (polaritons) at each site. We derive the system dynamics and show that is described by an XY Hamiltonian. We proceed by showing how to implement non-local quantum gates and show that combined with the inherent ability for individual addressing, universal quantum computation is possible in this system. We finally discuss the prospects for experimental implementation using various technologies involving dopants as atoms, quantum dots or Cooper pair boxes.