Altepeter J B, Hadley P G, Wendelken S M, Berglund A J, Kwiat P G
Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080, USA.
Phys Rev Lett. 2004 Apr 9;92(14):147901. doi: 10.1103/PhysRevLett.92.147901.
We thoroughly explore the phenomenon of a decoherence-free subspace (DFS) for two-qubit systems. Specifically, we both collectively and noncollectively decohere entangled polarization-encoded two-qubit states using thick birefringent crystals. These results characterize the basis-dependent effect of decoherence on the four Bell states, the robustness of the DFS state against perturbations in the assumption of collective decoherence, and the existence of a DFS for each type of stable noncollective decoherence. Finally, we investigate the effects of collective and noncollective dissipation.
