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Cloning of orthogonal mixed states entails irreversibility

Michal Horodecki·Aditi Sen De·Ujjwal Sen
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Abstract

Orthogonal pure states can be cloned as well as deleted. However if there is an initial disorder in the system, that is for orthogonal mixed states, one cannot perform deletion. And cloning, in such cases, necessarily produces an irreversibility, in the form of leakage of information into the environment.

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Michal Horodecki, Aditi Sen De, Ujjwal Sen. 2003-10-22. Cloning of orthogonal mixed states entails irreversibility. https://arxiv.org/abs/quant-ph/0310142

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