Efficient Quantum Algorithms for GHZ and W States, and Implementation on the IBM Quantum Computer
Diogo Cruz, Romain Fournier, Fabien Gremion, Alix Jeannerot, Kenichi N. Komagata, Tara N. Tošić, Jarla Thiesbrummel, Chun Lam Chan, Nicolas Macris, M.‐A. Dupertuis, Clément Javerzac‐Galy · Advanced Quantum Technologies · 2019
Abstract Efficient deterministic algorithms are proposed with logarithmic step complexities for the generation of entangled and states useful for quantum networks, and an implementation on the IBM quantum computer up to is demonstrated. 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. Robust states are built with about twice the number of quantum bits which were previously achieved.