Related Experiment Video
Updated: Jan 17, 2026

Demonstration of Spin-Multiplexed and Direction-Multiplexed All-Dielectric Visible Metaholograms
Published on: September 25, 2020
Active switching of chirality at exceptional points in terahertz metasurface and its multifunctional sensing
Abstract:
The missing dimensionality in the parameter space of non-Hermitian systems endows exceptional points (EPs) with inherent chirality, making EPs particularly valuable for ultrasensitive sensing, asymmetric optical transmission, and laser directional emission. Here we demonstrate dynamic chirality switching at three EPs in a single metasurface through temperature-controlled conductivity modulation of vanadium dioxide (VO2). Depending on the resonant field distributions of VO2 patches under low- and high-conductivity states, the system is modeled as either a tri-mode dual-port or bi-mode dual-port configuration. The Hamiltonian is constructed via coupled mode theory, and the eigenvalue and eigenstate evolution in polarization space are systematically analyzed. Based on EP in metasurface, three sensing schemes are designed for chiral enantiomer discrimination, refractive index, and temperature sensing, respectively. The proposed method provides a novel perspective for multi-EP design, chiral switching, and multifunctional sensing in metasurfaces, which can be extended to various non-Hermitian systems from microwave, infrared to visible light.
Related Concept Videos
Chirality in Nature
Chirality
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
Molecules with Multiple Chiral Centers
Prochirality
Chirality at Nitrogen, Phosphorus, and Sulfur
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...

