Experimental investigation of a two-qubit decoherence-free subspace.
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.
Altepeter
J B
JB
Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080, USA.
Hadley
P G
PG
Wendelken
S M
SM
Berglund
A J
AJ
Kwiat
P G
PG