Higher-order topological bound states in the continuum in a topoelectrical lattice with long-range coupling

TL;DR

This study uses electric circuit analogues of the 2D Su-Schrieffer-Heeger model to explore higher-order topological bound states in the continuum, demonstrating their robustness with long-range couplings and disorder.

Contribution

It introduces the analysis of long-range interactions in topoelectrical lattices preserving symmetries, revealing protected corner states in the continuum.

Findings

Corner-localized bound states remain protected by symmetry.

Long-range couplings do not destroy topological protection.

Circuit platforms can probe complex topological phenomena.

Abstract

Linear electric circuits composed of inductors and capacitors can serve as analogues of tight-binding models that describe the electronic band structure of materials. This mapping provides a versatile approach for exploring topological phenomena within engineered electrical lattices. In this work, the two-dimensional Su-Schrieffer-Heeger model is examined through electric circuit analogues to study the interplay between higher-order topology, bound states in the continuum, and disorder. Building upon this model, the effect of introducing next-nearest-neighbour interactions that preserve chiral and spatial symmetries of the system is analyzed. The results reveal that even without Hamiltonian separability, corner-localized bound states in the continuum remain protected by symmetry in the long-range coupled lattice. This robustness highlights the potential of circuit-based platforms for probing advanced topological phenomena in a highly controllable setting.