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arXiv · 0903.3077

Reversing the Weak Quantum Measurement for a Photonic Qubit

Yong-Su Kim·Young-Wook Cho·Young-Sik Ra·Yoon-Ho Kim
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Abstract

We demonstrate the conditional reversal of a weak (partial-collapse) quantum measurement on a photonic qubit. The weak quantum measurement causes a nonunitary transformation of a qubit which is subsequently reversed to the original state after a successful reversing operation. Both the weak measurement and the reversal operation are implemented linear optically. The state recovery fidelity, determined by quantum process tomography, is shown to be over 94% for partial-collapse strength up to 0.9. We also experimentally study information gain due to the weak measurement and discuss the role of the reversing operation as an information erasure.

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Yong-Su Kim, Young-Wook Cho, Young-Sik Ra, Yoon-Ho Kim. 2009-03-18. Reversing the Weak Quantum Measurement for a Photonic Qubit. https://doi.org/10.1364/oe.17.011978

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