The response of disordered matter to electromagnetic fields

TL;DR

This study reveals that various disordered materials exhibit a universal dielectric response across an extremely broad frequency spectrum, from millihertz to terahertz, including a superlinear power-law increase in conductivity.

Contribution

It demonstrates that the universal dielectric behavior of disordered matter extends into the GHz-THz range, covering frequencies previously thought to be outside this regime.

Findings

Universal dielectric response observed across all studied materials.

Superlinear power-law conductivity bridges classical dielectric and infrared regions.

Universal behavior extends from ultra-low to phonon frequencies.

Abstract

We have studied a variety of different disordered materials, including molecular and ionic liquids, supercooled liquids and glasses, ionic conductors, and doped semiconductors, in ac electromagnetic fields over an exceptional broad dynamic range including the rarely investigated GHz to THz region. We show that all classes of disordered matter exhibit an astonishingly similar response: In addition to Jonscher's time-honored "Universal Dielectric Response", a superlinear power-law increase of the frequency-dependent conductivity shows up bridging the gap between the classical dielectric and the infrared region. We demonstrate that the universal dielectric behavior of disordered matter extends up to much higher frequencies than thought until now and covers the range from ultra-low (mHz) to phonon (THz) frequencies.