Topological Lattice Metamaterials -- A Platform For Novel Electromagnetic Material Design Based On An Artificial Topological "Atom"

TL;DR

This paper introduces a novel approach to electromagnetic material design by using topologically non-trivial Mobius unknot structures as artificial atoms in metamaterials, enabling new control over GHz wave responses.

Contribution

It proposes using Mobius unknots as basic blocks for designing topological lattice metamaterials, a novel concept in electromagnetic material engineering.

Findings

Confirmed a 5.95 GHz intrinsic peak via experiments and simulations.

Demonstrated phase transition caused by wave propagation along Mobius structures.

Showed modulation of GHz response through coupling of potential and spin-like energy levels.

Abstract

In nature, most materials are composed of atoms with periodic structures. Hence, it's impossible to introduce topological structures into their lattice compose, because the atoms as basic blocks cannot be modulated. However, the lattice compose of metamaterials can be designed conveniently. In our work, we propose to introduce topological non-trivial structures, Mobius unknots, as the basic block (the artificial chiral "atoms") to design metamaterials. A 5.95 GHz intrinsic peak, in addition to the electrical resonance peak near 11 GHz on the transmission coefficient spectrum was confirmed by theoretical calculations, finite-difference time-domain (FDTD) simulations and experiments when electromagnetic waves transfer to a chiral Mobius unknot. Theoretical analysis indicates that this intrinsic peak originates from the phase transition caused by the electromagnetic waves propagate along the Mobius unknot non-trivial structure. It is similar to the state of spin-splitting of electron levels. Take the artificial chiral "atoms" - Mobius unknots as the basic block, we can construct two-dimensional and even three-dimensional ordered metamaterials. The simulation and experimental results showed that the response to electromagnetic wave in the GHz band can be modulated by the coupling between the periodic potential and the spin-like of energy levels.