Observation of higher-order time-dislocation topological modes

TL;DR

This paper reports the theoretical prediction and experimental observation of time-dislocation topological modes in a Floquet higher-order topological phase, revealing localized corner modes induced by temporal dislocations in a circuit metamaterial.

Contribution

It introduces the concept of time-dislocation topological modes and demonstrates their realization in a three-dimensional circuit metamaterial, expanding the understanding of topological phenomena involving time.

Findings

Observation of $\pi$-mode topological corner modes

Localization at temporal dislocation despite homogeneous couplings

Implementation of a 2D Floquet higher-order topological phase

Abstract

Topological dislocation modes resulting from the interplay between spatial dislocations and momentum-space topology have recently attracted significant interest. Here, we theoretically and experimentally demonstrate time-dislocation topological modes which are induced by the interplay between temporal dislocations and Floquet-band topology. By utilizing an extra physical dimension to represent the frequency-space lattice, we implement a two-dimensional Floquet higher-order topological phase and observe time-dislocation induced $\pi$-mode topological corner modes in a three-dimensional circuit metamaterial. Intriguingly, the realized time-dislocation topological modes exhibit spatial localization at the temporal dislocation, despite homogeneous in-plane lattice couplings across it. Our study opens a new avenue to explore the topological phenomena enabled by the interplay between real-space, time-space and momentum-space topology.