Finding a scalable and robust quantum computing architecture remains a challenge for both experimentalists and theoreticians. Over the last years, several strategies to overcome decoherence problems have been proposed. These include quantum error correction, topological quantum computing and the stabilisation of the desired time evolution through measurements and dissipation. Here we give an example for the latter approach and present a scheme for the build up of atomic cluster states via the observation of macroscopic fluorescence signals [1,2].
It is shown that the controlled generation of entanglement requires neither the coherent evolution of product states nor the detection of single photons . We predict high fidelities even in the presence of relatively large spontaneous decay rates.
 J. Metz, M. Trupke, and A. Beige, Robust entanglement through macroscopic quantum jumps, Phys. Rev. Lett. 97, 040503 (2006).
 J. Metz, C. Schoen, and A. Beige, Atomic cluster state build up with classical fluorescence signals (in preparation).