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 non-invasive 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 predictions from a 1/f noise model.
@article{arxiv.1008.3089,
title = {Quantum Coherence in a One-Electron Semiconductor Charge Qubit},
author = {K. D. Petersson and J. R. Petta and H. Lu and A. C. Gossard},
journal= {arXiv preprint arXiv:1008.3089},
year = {2013}
}