Quantum correlations in PT-symmetric systems

We study the dynamics of correlations in a paradigmatic setup to observe PT-symmetric physics: a pair of coupled oscillators, one subject to a gain one to a loss. Starting from a coherent state, quantum correlations (QCs) are created, despite the system being driven only incoherently, and can survive indefinitely. Both total and QCs exhibit different scalings of their long-time behavior in the PT-broken/unbroken phase and at the exceptional point (EP). In particular, PT symmetry breaking is accompanied by non-zero stationary QCs. This is analytically shown and quantitatively explained in terms of entropy balance. The EP in particular stands out as the most classical configuration, as classical correlations diverge while QCs vanish.

Automated summary

In a paradigmatic setup, researchers studied the dynamics of correlations to observe PT-symmetric physics, finding that quantum correlations exhibit different long-time behaviors in the PT-broken phase and at the exceptional points. At the exceptional point, classical correlations diverge while quantum correlations tend to zero.