Medford, James ReddingBeil, J.Taylor, J. M.Rashba, EmmanuelLu, H.Gossard, A. C.Marcus, C. M.2016-01-112013Medford, J., J. Beil, J. M. Taylor, E. I. Rashba, H. Lu, A. C. Gossard, and C. M. Marcus. 2013. “Quantum-Dot-Based Resonant Exchange Qubit.” Physical Review Letters 111 (5) (July). doi:10.1103/physrevlett.111.050501.0031-9007http://nrs.harvard.edu/urn-3:HUL.InstRepos:24082841We 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 π/2-gate time of 2.5 ns and a coherence time of 19  μs, using multipulse echo, are also demonstrated. Model calculations that include effects of hyperfine noise are in excellent quantitative agreement with experiment.en-USJournal Article2015-12-18J. Medford, J. Beil, J. M. Taylor, E. I. Rashba, H. Lu, A. C. Gossard, and C. M. Marcus2016-01-1110.1103/physrevlett.111.050501