Two-qubit interactions are at the heart of quantum information processing. For single-spin qubits in semiconductor quantum dots, the exchange gate has always been considered the natural two-qubit gate. The recent integration of magnetic field or g-factor gradients in coupled quantum dot systems allows for a one-step, robust realization of the controlled phase (C-Phase) gate instead. We analyze the C-Phase gate durations and fidelities that can be obtained under realistic conditions, including the effects of charge and nuclear field fluctuations, and find gate error probabilities of below 10-4, possibly allowing fault-tolerant quantum computation.
@article{arxiv.1010.0164,
title = {Efficient C-Phase gate for single-spin qubits in quantum dots},
author = {T. Meunier and V. E. Calado and L. M. K. Vandersypen},
journal= {arXiv preprint arXiv:1010.0164},
year = {2015}
}