Response of disordered matter to electromagnetic fields.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Dielectric Spectroscopy

Background:

• Disordered materials exhibit complex responses to electromagnetic fields.
• Jonscher's universal dielectric response describes behavior at lower frequencies.
• Understanding high-frequency dielectric properties is crucial for many applications.

Purpose of the Study:

• To investigate the dielectric response of various disordered materials.
• To explore the frequency-dependent conductivity in the GHz to THz range.
• To determine if universal dielectric behavior extends to higher frequencies.

Main Methods:

• Studied diverse disordered materials: molecular liquids, ionic liquids, supercooled liquids, glasses, ionic conductors, and doped semiconductors.
• Applied alternating current (ac) electromagnetic fields.
• Utilized a broad dynamic range, including the GHz to THz regions.

Main Results:

• All studied disordered materials showed a remarkably similar response.
• Observed a superlinear power-law increase in frequency-dependent conductivity.
• This conductivity increase bridges the gap between classical dielectric response and infrared absorption.

Conclusions:

• Universal dielectric behavior in disordered matter is more widespread than previously thought.
• The observed conductivity increase extends this universal behavior to much higher frequencies.
• Findings provide new insights into the electromagnetic response of disordered systems.