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arXiv · 2307.16496

Generic eigenstate preparation via measurement-based purification

Jia-shun Yan·Jun Jing
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Abstract

It is not a general opinion that that a quantum system could be purified into a target eigenstate via repeated measurements on a coupled qubit rather than direct transitions in the Hamiltonian. The projective measurement on the ancillary qubit gives rise to the positive operator-valued measures on the system that can filter out the unwanted states except the target one. In application, we discuss the measurement-based entanglement purification by which maximally entangled states (Bell states and Greenberger-Horne-Zeilinger states) can be distilled from the maximally mixed states or separable states. We also demonstrate the significant acceleration of a stimulated Raman adiabatic passage assisted by similar measurements. Our scheme allows arbitrary eigenstate preparation and reveals efficiency in multipartite systems for subspace purification. It offers a promising and generic quantum-control framework enriching the functionalities of quantum measurement.

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Jia-shun Yan, Jun Jing. 2023-07-31. Generic eigenstate preparation via measurement-based purification. https://doi.org/10.1103/physreva.108.042215

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