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arXiv:1008.3089 · Physical Review Letters

Quantum Coherence in a One-Electron Semiconductor Charge Qubit

Karl D. Petersson, J. R. Petta, Hong Lü, Arthur C. Gossard

Published Dec 8, 2010• 380 citations
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Abstract

We study quantum coherence in a semiconductor charge qubit formed from a GaAs double quantum dot containing a single electron. Voltage pulses are applied to depletion gates to drive qubit rotations and noninvasive state readout is achieved using a quantum point contact charge detector. We measure a maximum coherence time of ∼7 ns at the charge degeneracy point, where the qubit level splitting is first-order insensitive to gate voltage fluctuations. We compare measurements of the coherence time as a function of detuning with numerical simulations and predictions from a 1/f noise model.

DOI
10.1103/physrevlett.105.246804

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