Observation of flat-band localization and topological edge states induced by effective strong interactions in electrical circuit networks

TL;DR

This paper experimentally demonstrates how strong interactions in electrical circuit networks can induce flat-band localization and topological edge states, providing insights into interaction-driven topological phenomena.

Contribution

It presents the first experimental simulation of interaction-induced flat-band topologies and edge states using electrical circuits, mapping two-boson eigenstates to circuit modes.

Findings

Detection of two-boson flat-bands via impedance measurements

Observation of topological edge states in circuit networks

Mapping of correlated boson states to circuit eigenmodes

Abstract

Flat-band topologies and localizations in non-interacting systems are extensively studied in different quantum and classical-wave systems. Recently, the exploration on the novel physics of flat-band localizations and topologies in interacting systems has aroused great interest. In particular, it is theoretically shown that the strong-interaction could drive the formation of nontrivial topological flat bands, even dispersive trivial bands dominate the single-particle counterparts. However, the experimental observation of those interesting phenomena is still lacking. Here, we experimentally simulate the interaction-induced flat-band localizations and topological edge states in electrical circuit networks. We directly map the eigenstates of two correlated bosons in one-dimensional Aharonov Bohm cages to modes of two-dimensional circuit lattices.In this case, the two-boson flat-bands and topological edge states are detected by measuring frequency-dependent impedance responses and voltage dynamics in the time domain. Our finding suggests a flexible platform to simulate the interaction-induced flat-band topology, and may possess potential applications in designing novel electronic devices.