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Decoherence in a N-qubit solid-state quantum computer

B. Ischi·M. Hilke·M. Dube
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Abstract

We investigate the decoherence process for a quantum register composed of N qubits coupled to an environment. We consider an environment composed of one common phonon bath and several electronic baths. This environment is relevant to the implementation of a charge based solid-state quantum computer. We explicitly compute the time evolution of all off-diagonal terms of the register's reduced density matrix. We find that in realistic configurations, "superdecoherence" and "decoherence free subspaces" do not exist for an N-qubit system. This means that all off-diagonal terms decay like exp(-q(t)N), where q(t) is of the same order as the decay function of a single qubit.

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B. Ischi, M. Hilke, M. Dube. 2005-06-11. Decoherence in a N-qubit solid-state quantum computer. https://doi.org/10.1103/physrevb.71.195325

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