Information retrieval and criticality in high-dimensional parity-time-symmetric systems

Recently, impressive progress has been made in the study of non-Hermitian systems with parity-time symmetry, such as observations of topological properties of physical systems and criticality at exceptionalpoints. A crucial aspect of parity-time symmetric nonunitary dynamics is the information flow between thesystem and the environment. In this paper, we use the physical quantity, distinguishability between quantumstates, to uniformly quantify the information flow between low-dimensional and high-dimensional parity-timesymmetric non-Hermitian systems and environments. The numerical results show that the oscillation ofquantum state distinguishability and complete information retrieval and can be obtained in the parity-time-unbroken phase. However, the information decays exponentially in the parity-time-broken phase. Theexceptional point marks the criticality between reversibility and irreversibility of information flow, and thedistinguishability between quantum states exhibits the behavior of power-law decay. Understanding theseunique phenomena in nonunitary quantum dynamics provides an important perspective for the study of openquantum systems and contributes to their application in quantum information