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arXiv · 2507.08676

Magic Steady State Production: Non-Hermitian, Dissipative, and Stochastic Pathways

Pablo Martinez-Azcona·Matthieu Sarkis·Alexandre Tkatchenko·Aurélia Chenu
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Abstract

Universal quantum computers require entanglement and non-stabilizerness, a resource known as \textit{quantum magic}. Here, we introduce a protocol that prepares magic steady states by leveraging non-Hermitian dynamics, which, contrary to unitary dynamics, can host pure-state attractors. By studying the dissipative qubit, we find the optimal parameters to prepare $|H\rangle$ and $|T\rangle$ steady states. Interestingly, this approach does not require knowledge or preparation of a particular initial state, since all the states of the Bloch sphere converge to the engineered target steady state. We also consider the addition of classical noise in the anti-hermitian part and provide the regimes for which the noisy dynamics still converges to high magic states. We also introduce a dissipative protocol to prepare magic steady states, compare the approaches with magic state cultivation and provide a particular realization of the non-Hermitian scheme in a cat qubit.

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Pablo Martinez-Azcona, Matthieu Sarkis, Alexandre Tkatchenko, Aurélia Chenu. 2025-07-11. Magic Steady State Production: Non-Hermitian, Dissipative, and Stochastic Pathways. https://arxiv.org/abs/2507.08676

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