Experimental application of decoherence-free subspaces in an optical quantum-computing algorithm.
For a practical quantum computer to operate, it is essential to properly manage decoherence. One important technique for doing this is the use of "decoherence-free subspaces" (DFSs), which have recently been demonstrated. Here we present the first use of DFSs to improve the performance of a quantum algorithm. An optical implementation of the Deutsch-Jozsa algorithm can be made insensitive to a particular class of phase noise by encoding information in the appropriate subspaces; we observe a reduction of the error rate from 35% to 7%, essentially its value in the absence of noise.
Mohseni
M
M
Department of Physics, University of Toronto, 60 St. George Street, Toronto, Ontario, Canada, M5S 1A7.
Lundeen
J S
JS
Resch
K J
KJ
Steinberg
A M
AM