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Conference on Lasers and Electro-Optics

Observation of PT symmetry breaking in two-photon correlations

Friederike Klauck, Matthias Heinrich, Alexander Szameit

Published Jan 1, 2021• 0 citations
Publisher

Abstract

We experimentally study the influence of PT-symmetry breaking on two-photon correlations in quasi-PT-symmetric couplers. While quantum interference is faithfully preserved in the unbroken phase. a characteristic rise of off-diagonal terms occurs beyond the exceptional point.
DOI
10.1364/cleo_qels.2021.fth2j.5

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Abstract 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.
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