Selective Filtering of Photonic Quantum Entanglement via Anti-Parity-Time Symmetry

Abstract

Entanglement is a key resource for quantum computing, sensing, and communication, however it is highly susceptible to decoherence. To address this, quantum optics has explored filtering techniques like photon ancillas and Rydberg atom blockade to restore entangled states. Here, we introduce a an entirely new approach to entanglement retrieval exploiting non-Hermitian systems. By employing an anti-parity-time two-state guiding configuration, we demonstrate efficient extraction of entanglement from any input state. This filter is implemented on a lossless waveguide network using Lanczos transformations, consistent with Wigner-Weisskopf theory. This scheme achieves near-unity fidelity under single- and two-photon excitation and is scalable to higher photon levels while remaining robust against decoherence during propagation. Our work offers new insights into using non-Hermitian symmetries to address central challenges in quantum technologies.

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Cited by in corpus (6)

• Dark-state photonic entanglement filters
• Exact dynamics and bound states of a cavity coupled to a two-dimensional reservoir
• Non-Hermitian topological filters
• Scattering States in One-Dimensional Non-Hermitian Baths
• Advancements in Entangled Photon Pairs in 2D Van der Waals Materials for On-chip Quantum Applications
• Non-Hermiticity induced thermal entanglement phase transition