LETTER TO THE EDITOR: Using continuous measurement to protect a universal set of quantum gates within a perturbed decoherence-free subspace
Abstract
We consider a universal set of quantum gates encoded within a perturbed decoherence-free subspace of four physical qubits. Using second-order perturbation theory and a measuring device modelled by an infinite set of harmonic oscillators, simply coupled to the system, we show that continuous observation of the coupling agent induces inhibition of the decoherence due to spurious perturbations. We thus advance the idea of protecting or even creating a decoherence-free subspace for processing quantum information.
- Publication:
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Journal of Physics A Mathematical General
- Pub Date:
- February 2005
- DOI:
- 10.1088/0305-4470/38/6/L04
- arXiv:
- arXiv:quant-ph/0501064
- Bibcode:
- 2005JPhA...38L..95M
- Keywords:
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- Quantum Physics
- E-Print:
- 7 pages, 1 figure. To be published in Journal of Physics A: Mathematical and General