title: Quantum-dot-based resonant exchange qubit.
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 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.
authors: Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
authors: J
authors: J
authors: Medford
authors: J
authors: J
authors: Beil
authors: J M
authors: JM
authors: Taylor
authors: E I
authors: EI
authors: Rashba
authors: H
authors: H
authors: Lu
authors: A C
authors: AC
authors: Gossard
authors: C M
authors: CM
authors: Marcus