Observation of higher-order time-dislocation topological modes.

Area of Science:

• Condensed Matter Physics
• Topological Materials Science
• Metamaterials

Background:

• Spatial dislocations and momentum-space topology have driven interest in topological dislocation modes.
• Floquet band topology offers a framework for understanding time-dependent topological phenomena.

Purpose of the Study:

• To theoretically and experimentally demonstrate time-dislocation topological modes.
• To explore the interplay between temporal dislocations and Floquet band topology.
• To investigate the spatial localization of these novel topological modes.

Main Methods:

• Theoretical modeling of time-dislocation topological modes.
• Experimental implementation using a three-dimensional circuit metamaterial.
• Utilizing an extra physical dimension to represent a frequency-space lattice.
• Observation of topological corner modes in a two-dimensional Floquet higher-order topological phase.

Main Results:

• Successful demonstration of time-dislocation topological modes.
• Observation of time-dislocation induced π-mode topological corner modes.
• Exhibition of spatial localization of topological modes at the temporal dislocation.
• Homogeneous in-plane lattice couplings across the temporal dislocation were confirmed.

Conclusions:

• The study establishes time-dislocation topological modes as a new class of topological phenomena.
• This work highlights the potential of combining real-space, time-space, and momentum-space topology.
• Opens new research directions in topological physics and metamaterials.