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Reversible quantum measurement with arbitrary spins

Hiroaki Terashima·Masahito Ueda
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Abstract

We propose a physically reversible quantum measurement of an arbitrary spin-s system using a spin-j probe via an Ising interaction. In the case of a spin-1/2 system (s=1/2), we explicitly construct a reversing measurement and evaluate the degree of reversibility in terms of fidelity. The recovery of the measured state is pronounced when the probe has a high spin (j>1/2), because the fidelity changes drastically during the reversible measurement and the reversing measurement. We also show that the reversing measurement scheme for a spin-1/2 system can serve as an experimentally feasible approximate reversing measurement for a high-spin system (s>1/2). If the interaction is sufficiently weak, the reversing measurement can recover a cat state almost deterministically in spite of there being a large fidelity change.

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Hiroaki Terashima, Masahito Ueda. 2006-05-22. Reversible quantum measurement with arbitrary spins. https://doi.org/10.1103/physreva.74.012102

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