Robust generation of entanglement between two cavities mediated by short interactions with an atom

Current methods of preparing maximally entangled states in the laboratory need an extremely accurate control of interaction times, requiring sophisticated experimental techniques. Here, we show that such precise control is not necessary when one utilizes short or weak interactions followed by measurements. We present a scheme for the probabilistic generation of Bell states in a pair of cavities, after each has interacted briefly with an atom. The advantage of this proposal, as compared to present schemes, is its low sensitivity to the exact values of experimental parameters such as atomic velocity and coupling strength, in fact, for a large range of parameters the fidelity of the Bell states generated remains close to unity.