Dynamic Chiral Magnetic Effect and Faraday Rotation in Macroscopically Disordered Helical Metals

Area of Science:

• Condensed Matter Physics
• Electromagnetism
• Materials Science

Background:

• Electromagnetic wave propagation in materials is influenced by their conductivity.
• Chiral magnetic effects introduce unique responses to electromagnetic waves.
• Understanding disorder effects is crucial for predicting material properties.

Purpose of the Study:

• To develop an effective medium theory for electromagnetic wave propagation in gapless nonuniform systems with a dynamic chiral magnetic effect.
• To quantify disorder-induced corrections to optical and chiral magnetic conductivities.
• To investigate the impact of these corrections on observable optical signals.

Main Methods:

• Development of an effective medium theory.
• Calculation of macroscopic-disorder-induced corrections.
• Analysis of spatial fluctuations in optical conductivity.
• Frequency dependence analysis of polarization rotation and circular dichroism.

Main Results:

• The theory successfully calculates disorder corrections to optical and chiral magnetic conductivities.
• Spatial fluctuations in optical conductivity correct the effective chiral magnetic conductivity.
• These corrections dictate the leading frequency dependence of polarization rotation and circular dichroism.
• Observable features are predicted in Faraday rotation near bulk plasmon resonances.

Conclusions:

• Macroscopic disorder significantly impacts electromagnetic wave propagation in dynamic chiral magnetic systems.
• The developed theory provides a framework for understanding these effects.
• Experimental observation of predicted features in Faraday rotation could validate the theory and distinguish from single-crystal behavior.