Bulk-spatiotemporal vortex correspondence in gyromagnetic zero-index media

Area of Science:

• Metamaterials
• Topological Photonics
• Singular Optics

Background:

• Double-zero-index media exhibit unique properties due to zero permittivity and permeability.
• Generalizing zero index to non-reciprocal tensors expands possibilities beyond natural materials.

Purpose of the Study:

• To experimentally realize gyromagnetic double-zero-index metamaterials with non-reciprocal features.
• To establish a bulk-spatiotemporal vortex correspondence anchored to topological phase transitions.
• To demonstrate deterministic generation of ultrarobust optical spatiotemporal vortex pulses.

Main Methods:

• Experimental realization of gyromagnetic double-zero-index metamaterials.
• Investigation of spin-1/2 Dirac points and topological phase transitions.
• Demonstration of spatiotemporal reflection vortex singularities anchored to Dirac points.

Main Results:

• Successful creation of metamaterials with both double-zero-index and non-reciprocal properties.
• Discovery of spatiotemporal reflection vortex singularities linked to topological phase transitions.
• Deterministic generation of optical spatiotemporal vortex pulses with fixed frequency and momentum.

Conclusions:

• Established a novel bulk-spatiotemporal vortex correspondence, extending boundary effects into the time domain.
• Uncovered connections between zero-refractive-index photonics, topological photonics, and singular optics.
• Proposed a pathway for manipulating space-time topological light fields using extreme-parameter metamaterials.