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Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
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Programmable state switching based on higher-order exceptional points in anti-parity-time symmetric microcavity
Arnab Laha1, Dinesh Beniwal2, Somnath Ghosh3
1Institute of Spintronics and Quantum Information, Faculty of Physics and Astronomy, Adam Mickiewicz University, 61-614, Poznan, Poland. arnablaha777@gmail.com.
Scientific Reports
|September 25, 2025
Summary
Researchers explored anti-parity-time (APT) symmetry in metamaterial microcavities. They revealed topological properties of exceptional points (EPs) in negative-indexed media, enabling novel photonic devices.
Area of Science:
- Photonics
- Metamaterials
- Non-Hermitian Physics
Background:
- Traditional parity-time (PT) symmetry is limited. Anti-PT (APT) symmetry offers new ways to control light-matter interactions.
- Negative-index materials, often metamaterials, are key for artificial photonic systems.
- Fabry-Pérot microcavities provide a platform for exploring novel physical phenomena.
Purpose of the Study:
- To investigate anti-PT symmetry in a specially configured Fabry-Pérot microcavity.
- To explore the topological properties of exceptional points (EPs) in negative-indexed media.
- To demonstrate programmable adiabatic state-switching using gain-loss parameters.
Main Methods:
- Utilized a Fabry-Pérot microcavity with negative-indexed background materials.
- Implemented balanced gain-loss distributions to achieve anti-PT symmetry.
- Analyzed topological properties of second-order (EP2) and third-order (EP3) exceptional points.
Main Results:
- Unveiled topological properties of a parametrically encircled third-order EP (EP3) emerging from two connected second-order EPs (EP2s).
- Demonstrated a programmable adiabatic state-switching process.
- Highlighted nuanced behaviors of second and third-order branch points in a 2D gain-loss parameter space.
Conclusions:
- The study provides theoretical foundations for topological properties of EPs in negative-indexed media.
- This work paves the way for novel metamaterial-based artificial photonic devices.
- Explores advanced non-Hermitian physics in engineered optical systems.
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