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arXiv · 2007.00368

Quantum optimal control with quantum computers: an hybrid algorithm featuring machine learning optimization

Davide Castaldo·Marta Rosa·Stefano Corni
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Abstract

We develop an hybrid quantum-classical algorithm to solve an optimal population transfer problem for a molecule subject to a laser pulse. The evolution of the molecular wavefunction under the laser pulse is simulated on a quantum computer, while the optimal pulse is iteratively shaped via a machine learning (evolutionary) algorithm. A method to encode on the quantum computer the n-electrons wavefunction is discussed, the circuits accomplishing its quantum simulation are derived and the scalability in terms of number of operations is discussed. Performance on Noisy Intermediate-Scale Quantum devices (IBM Q X2) is provided to assess the current technological gap. Furthermore the hybrid algorithm is tested on a quantum emulator to compare performance of the evolutionary algorithm with standard ones. Our results show that such algorithms are able to outperform the optimization with a downhill simplex method and provide performance comparable to more advanced (but quantum-computer unfriendly) algorithms such as Rabitz's.

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Davide Castaldo, Marta Rosa, Stefano Corni. 2021-02-24. Quantum optimal control with quantum computers: an hybrid algorithm featuring machine learning optimization. https://doi.org/10.1103/physreva.103.022613

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