Dual opposing quadrature-PT symmetry

• DOI: 10.48550/arxiv.2405.15612
• Publication Date: 2025-01-01
• Authors: Wencong Wang; Jacob Kokinda; Jiazhen Li; Qing Gu; Dongmei Liu; Jianming Wen
• Keywords: Quantum Physics; Physics; Science; Natural sciences; Quantum physics; Q; FOS: Physical sciences; Quantum Physics (quant-ph); Article

Our recent research on type-I quadrature parity-time (PT) symmetry, utilizing an open twin-beam system, not only enables observing genuine quantum photonic PT symmetry amid phase-sensitive amplification (PSA) and loss in the presence of Langevin noise but also reveals additional classical-to-quantum (C2Q) transitions in quadrature and relative-intensity noise fluctuations. In contrast to the previous setup, our exploration of an alternative system assuming no loss involves a type-II PSA-only scheme. This scheme facilitates dual opposing quadrature PT symmetry, offering a comprehensive and complementary comprehension of C2Q transitions and anti-Hermiticity-enhanced quantum sensing. Furthermore, our investigation into the correlation with the Einstein-Podolsky-Rosen criteria uncovers previously unexplored connections between PT symmetry and nonclassicality, as well as quantum entanglement within the continuous-variable framework.<br/>This is type-II quadrature PT symmetry, compared to type-I quadrature PT symmetry (arXiv:2301.05511)<br/>