Abstract
Multielectron spin qubits are demonstrated, and performance examined by comparing coherent exchange oscillations in coupled single-electron and multielectron quantum dots, measured in the same device. Fast (>1 GHz) exchange oscillations with a quality factor Q ∼ 15 are found for the multielectron case, compared to Q ∼ 2 for the single-electron case, the latter consistent with experiments in the literature. A model of dephasing that includes voltage and hyperfine noise is developed that is in good agreement with both single- and multielectron data, though in both cases additional exchange-independent dephasing is needed to obtain quantitative agreement across a broad parameter range.
Originalsprog | Engelsk |
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Artikelnummer | 026801 |
Tidsskrift | Physical Review Letters |
Vol/bind | 112 |
Antal sider | 5 |
ISSN | 0031-9007 |
DOI | |
Status | Udgivet - 14 jan. 2014 |