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arXiv · 1705.04628

Information Retrieval and Criticality in Parity-Time-Symmetric Systems

Kohei Kawabata·Yuto Ashida·Masahito Ueda
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Abstract

By investigating information flow between a general parity-time (PT) -symmetric non-Hermitian system and an environment, we find that the complete information retrieval from the environment can be achieved in the PT-unbroken phase, whereas no information can be retrieved in the PT-broken phase. The PT-transition point thus marks the reversible-irreversible criticality of information flow, around which many physical quantities such as the recurrence time and the distinguishability between quantum states exhibit power-law behavior. Moreover, by embedding a PT-symmetric system into a larger Hilbert space so that the entire system obeys unitary dynamics, we reveal that behind the information retrieval lies a hidden entangled partner protected by PT symmetry. Possible experimental situations are also discussed.

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Kohei Kawabata, Yuto Ashida, Masahito Ueda. 2017-11-06. Information Retrieval and Criticality in Parity-Time-Symmetric Systems. https://doi.org/10.1103/physrevlett.119.190401

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