Giant Cotton-Mouton effect of suspensions of iron nanorods

TL;DR

This paper theoretically predicts a giant Cotton-Mouton effect in suspensions of iron nanorods in the THz region, with potential for significant applications in magneto-optic materials.

Contribution

It introduces a theoretical model showing a giant CM effect in iron nanorod suspensions due to their dual ferromagnetic and plasmonic nature, unprecedented in magnitude.

Findings

Large linear birefringence up to 0.10 with 20 mT magnetic field

CM coefficient of 2.2×10^7 T^-2·m^-1, four orders larger than optical range

Potential for new THz magneto-optic applications

Abstract

The Cotton-Mouton (CM) effect, referring to linear birefringence induced by a magnetic field, is usually very weak in natural materials. We propose theoretically that a giant CM effect may be achieved in the THz region with the suspension of iron nanorods. The unusual effect stems from the dual nature of the iron nanorods, which exhibit both ferromagnetic and plasmonic characteristics. Our results suggest that, with an ultralow magnetic field of 20 mT, a large linear birefringence up to 0.10 can be realized. The CM coefficient attains 2.2*10 7 T-2m-1, four orders of magnitude larger than that obtained currently in optical range. The results may advance the study and applications of the THz CM effect in artificial magneto-optic materials.