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Practical purification scheme for decohered coherent-state superpositions via partial homodyne detection

Shigenari Suzuki·Masahiro Takeoka·Masahide Sasaki·Ulrik L. Andersen·Fumihiko Kannari
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Abstract

We present a simple protocol to purify a coherent-state superposition that has undergone a linear lossy channel. The scheme constitutes only a single beam splitter and a homodyne detector, and thus is experimentally feasible. In practice, a superposition of coherent states is transformed into a classical mixture of coherent states by linear loss, which is usually the dominant decoherence mechanism in optical systems. We also address the possibility of producing a larger amplitude superposition state from decohered states, and show that in most cases the decoherence of the states are amplified along with the amplitude.

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Shigenari Suzuki, Masahiro Takeoka, Masahide Sasaki, Ulrik L. Andersen, Fumihiko Kannari. 2006-08-02. Practical purification scheme for decohered coherent-state superpositions via partial homodyne detection. https://doi.org/10.1103/physreva.73.042304

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