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arXiv · 2112.04242

Unification of Random Dynamical Decoupling and the Quantum Zeno Effect

Alexander Hahn·Daniel Burgarth·Kazuya Yuasa
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Abstract

Periodic deterministic bang-bang dynamical decoupling and the quantum Zeno effect are known to emerge from the same physical mechanism. Both concepts are based on cycles of strong and frequent kicks provoking a subdivision of the Hilbert space into independent subspaces. However, previous unification results do not capture the case of random bang-bang dynamical decoupling, which can be advantageous to the deterministic case but has an inherently acyclic structure. Here, we establish a correspondence between random dynamical decoupling and the quantum Zeno effect by investigating the average over random decoupling evolutions. This protocol is a manifestation of the quantum Zeno dynamics and leads to a unitary bath evolution. By providing a framework that we call equitability of system and bath, we show that the system dynamics under random dynamical decoupling converges to a unitary with a decoupling error that characteristically depends on the convergence speed of the Zeno limit. This reveals a unification of the random dynamical decoupling and the quantum Zeno effect.

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Alexander Hahn, Daniel Burgarth, Kazuya Yuasa. 2021-12-08. Unification of Random Dynamical Decoupling and the Quantum Zeno Effect. https://doi.org/10.1088/1367-2630%2Fac6b4f

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