Topological phase transitions in a constrained two-qubit quantum control landscape

• URL: http://arxiv.org/abs/2411.08736v1
• Date: Wed, 13 Nov 2024 16:18:41 GMT
• Title: Topological phase transitions in a constrained two-qubit quantum control landscape
• Authors: Nicolò Beato, Pranay Patil, Marin Bukov,
• Abstract summary: In optimal quantum control, control landscape phase transitions (Cs) indicate sharp changes occurring in the set of optimal protocols. We demonstrate the existence of a new class of CLPTs, associated with changes in the topological properties of the optimal level set in a two-qubit state-preparation problem.
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• Abstract: In optimal quantum control, control landscape phase transitions (CLPTs) indicate sharp changes occurring in the set of optimal protocols, as a physical model parameter is varied. Here, we demonstrate the existence of a new class of CLPTs, associated with changes in the topological properties of the optimal level set in a two-qubit state-preparation problem. In particular, the distance distribution of control protocols sampled through stochastic homotopic dynamics reveals discontinuous changes in the number of connected components in the optimal level set, as a function of the protocol duration. We demonstrate how topological CLPTs can be detected in modern-day experiments.

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