Topological nodal states in circuit lattice

TL;DR

This paper proposes a tunable 3D LC circuit lattice to realize topological semimetal states, including nodal-line and Weyl states, with stable topological features and characteristic surface bands.

Contribution

It introduces a novel circuit-based platform to emulate topological semimetal states with tunable parameters and analyzes their topological properties using a derived tight-binding-like model.

Findings

Realization of topological nodal-line and Weyl states in LC circuit lattices.

Identification of characteristic surface bands such as drumhead and Fermi-arc.

Weyl points remain stable despite fabrication errors.

Abstract

The search for artificial structure with tunable topological properties is an interesting research direction of today's topological physics. Here, we introduce a scheme to realize `topological semimetal states' with a three-dimensional periodic inductor-capacitor (LC) circuit lattice, where the topological nodal-line state and Weyl state can be achieved by tuning the parameters of inductors and capacitors. A tight-binding-like model is derived to analyze the topological properties of the LC circuit lattice. The key characters of the topological states, such as the drumhead-like surface bands for nodal-line state and the Fermi-arc-like surface bands for Weyl state, are found in these systems. We also show that the Weyl points are stable with the fabrication errors of electric devices.