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.
Original language | English |
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Article number | 026801 |
Journal | Physical Review Letters |
Volume | 112 |
Number of pages | 5 |
ISSN | 0031-9007 |
DOIs | |
Publication status | Published - 14 Jan 2014 |