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arXiv · 1304.3413

The Resonant Exchange Qubit

J. Medford·J. Beil·J. M. Taylor·E. I. Rashba·H. Lu·A. C. Gossard·C. M. Marcus
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Abstract

We introduce a solid-state qubit in which exchange interactions among confined electrons provide both the static longitudinal field and the oscillatory transverse field, allowing rapid and full qubit control via rf gate-voltage pulses. We demonstrate two-axis control at a detuning sweet-spot, where leakage due to hyperfine coupling is suppressed by the large exchange gap. A {\pi}/2-gate time of 2.5 ns and a coherence time of 19 {\mu}s, using multi-pulse echo, are also demonstrated. Model calculations that include effects of hyperfine noise are in excellent quantitative agreement with experiment.

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J. Medford, J. Beil, J. M. Taylor, E. I. Rashba, H. Lu, A. C. Gossard, C. M. Marcus. 2013-04-11. The Resonant Exchange Qubit. https://doi.org/10.1103/physrevlett.111.050501

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