Electrodynamics of correlated electron matter

TL;DR

Infrared spectroscopy reveals complex electrodynamic behaviors in strongly correlated electron materials, highlighting deviations from simple metallic responses due to phenomena like charge ordering, phase transitions, and bosonic mode coupling.

Contribution

This paper reviews recent advances in infrared spectroscopy studies of correlated electron systems, emphasizing common patterns and unconventional electrodynamic responses.

Findings

Unconventional electrodynamics in correlated materials

Evidence of charge and spin ordering effects

Strong coupling to bosonic modes influences responses

Abstract

Infrared spectroscopy has emerged as a premier experimental technique to probe enigmatic effects arising from strong correlations in solids. Here we report on recent advances in this area focusing on common patterns in correlated electron systems including transition metal oxides, intermetallics and organic conductors. All these materials are highly conducting substances but their electrodynamic response is profoundly different from the canonical Drude behavior observed in simple metals. These unconventional properties can be attributed in several cases to the formation of spin and/or charge ordered states, zero temperature phase transitions and strong coupling to bosonic modes.