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arXiv · 1909.09289

Optimal preparation of the $W$ state for qubits with XY coupling

Dalton Jones·Armin Rahmani
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Abstract

Using simulated annealing, we find optimal protocols that evolve a simple product state into a three-qubit $W$ state with a Hamiltonian that describes XY coupling and single-qubit gates, and determine the associated quantum speed limit. Applying Pontryagin's minimum principle, we fully characterize the optimal bang-bang protocols. While leakage affects performance, the protocols remain robust to implementation errors and operate well within relaxation and decoherence times. Our findings highlight Pontryagin's principle as a powerful tool for designing pulse shapes that directly link device interactions to specific quantum gates and target states.

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Dalton Jones, Armin Rahmani. 2019-09-20. Optimal preparation of the $W$ state for qubits with XY coupling. https://doi.org/10.1209/0295-5075%2Fae5c32

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