Terahertz metamaterials for light-driven magnetism

TL;DR

This paper presents the design of two metamaterials, a 'dragonfly' antenna and an octopole antenna, that significantly enhance terahertz magnetic and electric fields, enabling control of magnetic states in condensed matter systems.

Contribution

The paper introduces novel metamaterial designs that amplify terahertz fields by five times, facilitating stronger magnetic and electric field interactions in condensed matter research.

Findings

Five-fold enhancement of terahertz magnetic fields exceeding 1 T.

Five-fold enhancement of electric fields exceeding 1 MV/cm.

Structures are easily fabricable on various materials.

Abstract

We describe the design of two types of metamaterials aimed at enhancing terahertz field pulses that can be used to control the magnetic state in condensed matter systems. The first structure is a so-called "dragonfly" antenna, able to realize a five-fold enhancement of the impinging terahertz magnetic field, while preserving its broadband features. For currently available state-of-the-art table top sources, this leads to peak magnetic fields exceeding 1 T. The second structure is an octopole antenna aimed at enhancing a circularly-polarized terahertz electric field, while preserving its polarization state. We obtain a five-fold enhancement of the electric field, hence expected to exceed the 1 MV/cm peak amplitude. Both our structures can be readily fabricated on top of virtually any material.