Related Experiment Video
Updated: Jun 3, 2025

Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
Crossing exceptional points in non-Hermitian quantum systems
Friederike U J Klauck1, Matthias Heinrich1, Alexander Szameit1
1Institute of Physics, University of Rostock, Rostock, Germany.
Abstract:
Exceptional points facilitate peculiar dynamics in non-Hermitian systems. Yet, in photonics, they have mainly been studied in the classical realm. In this work, we reveal the behavior of two-photon quantum states in non-Hermitian systems across the exceptional point. We probe the lossy directional coupler with an indistinguishable two-photon input state and observe distinct changes of the quantum correlations at the output as the system undergoes spontaneous breaking of parity-time symmetry. Moreover, we demonstrate a switching in the quantum interference of photons directly at the exceptional point, where Hong-Ou-Mandel dips are transformed into peaks by a change of basis. These results show that quantum interference and exceptional points are linked in curious ways that can now be further explored.
More Related Videos
Related Concept Videos
Second Uniqueness Theorem
In contrast, consider that the electric field is non-unique and apply Gauss's law in divergence form in the region between the conductors and the integral form to the...
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
¹H NMR Signal Multiplicity: Splitting Patterns
Symmetry in Maxwell's Equations
Divergence and Curl of Electric Field

