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Stabilizing qubit coherence via tracking-control

Daniel A. Lidar·Sara Schneider
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Abstract

We consider the problem of stabilizing the coherence of a single qubit subject to Markovian decoherence, via the application of a control Hamiltonian, without any additional resources. In this case neither quantum error correction/avoidance, nor dynamical decoupling applies. We show that using tracking-control, i.e., the conditioning of the control field on the state of the qubit, it is possible to maintain coherence for finite time durations, until the control field diverges.

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Daniel A. Lidar, Sara Schneider. 2004-10-06. Stabilizing qubit coherence via tracking-control. https://arxiv.org/abs/quant-ph/0410048

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