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arXiv:cond-mat/0511162 · Physical Review B

Partly noiseless encoding of quantum information in quantum dot arrays against phonon-induced pure dephasing

Anna Grodecka, Paweł Machnikowski

Published Mar 8, 2006• 49 citations
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Abstract

We show that pure dephasing of a quantum dot charge (excitonic) qubit may be reduced for sufficiently slow gating by collectively encoding quantum information in an array of quantum dots. We study the role of the size and structure of the array and of the exciton lifetime for the resulting total error of a single-qubit operation.
DOI
10.1103/physrevb.73.125306

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We show that phonon-induced pure dephasing of an excitonic (charge) quantum bit in a quantum dot (QD) may be reduced by collective encoding of logical qubits in QD arrays. We define the logical qubit on an array of 2, 4 and 8 QDs, connecting the logical |0⟩ state with the presence of excitons in the appropriately chosen half of dots and the logical |1⟩ state with the other half of the dots occupied. We give quantitative estimates of the resulting total error of a single qubit operation for an InAs/GaAs system.
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