Generating entanglement by measurement in circuit QED

In this talk, I will show theoretically how to induce entanglement by measurement in circuit QED. I will use quantum trajectory theory to derive an equation for the conditional state of a two qubit system, conditioned on continuous-in-time measurement of the amplitude and phase of the field leaving the resonator. I will show that with experimental parameters, we can use a decoherence-free subspace to generate an entangled state with a high concurrence and with a success probability of 1/2. Finally I will show that with a simple feedback scheme the same concurrence can be achieved with a success probability of one.