We propose efficient algorithms with logarithmic step complexities for the generation of entangled GHZN and WN states useful for quantum networks, and we demonstrate an implementation on the IBM quantum computer up to N=16. Improved quality is then investigated using full quantum tomography for low-N GHZ and W states. This is completed by parity oscillations and histogram distance for large N GHZ and W states respectively. We are capable to robustly build states with about twice the number of quantum bits which were previously achieved. Finally we attempt quantum error correction on GHZ using recent schemes proposed in the literature, but with the present amount of decoherence they prove detrimental.
@article{arxiv.1807.05572,
title = {Efficient quantum algorithms for $GHZ$ and $W$ states, and implementation on the IBM quantum computer},
author = {Diogo Cruz and Romain Fournier and Fabien Gremion and Alix Jeannerot and Kenichi Komagata and Tara Tosic and Jarla Thiesbrummel and Chun Lam Chan and Nicolas Macris and Marc-André Dupertuis and Clément Javerzac-Galy},
journal= {arXiv preprint arXiv:1807.05572},
year = {2019}
}