Quantum control for error correction is critical for the practical use of quantum computers. We address quantum optimal control for single-shot multi-qubit gates by framing as a feasibility problem for the Hamiltonian model and then solving with standard global-optimization software. Our approach yields faster high-fidelity (>99.99\%) single-shot three-qubit-gate control than obtained previously, and our method has enabled us to solve the quantum-control problem for a fast high-fidelity four-qubit gate.
@article{arxiv.1805.03569,
title = {Quantum control for high-fidelity multi-qubit gates},
author = {Raymond J. Spiteri and Marina Schmidt and Joydip Ghosh and Ehsan Zahedinejad and Barry C. Sanders},
journal= {arXiv preprint arXiv:1805.03569},
year = {2019}
}