Magnetostatics and optics of noncentrosymmetric metals

TL;DR

This paper investigates the magneto-optical properties of noncentrosymmetric metals, revealing how their unique gyrotropic response affects phenomena like the Kerr effect, with implications for high-temperature superconductors.

Contribution

It provides a theoretical analysis of gyrotropic currents in noncentrosymmetric metals, linking static and high-frequency responses to observable optical effects.

Findings

Static gyrotropic current has negligible effect on London magnetostatics.

High-frequency response explains observed Kerr effect in high Tc materials.

Theoretical Kerr angle estimates match experimental observations.

Abstract

The current in noncentrosymmetric metals in normal and superconducting state is found in frame of linear response theory. In line with usual terms corresponding diamagnetic response, the Landau diamagnetism and the Pauli paramagnetism the general expression contains also the terms corresponding to spacial dispersion specific for a medium without space parity. This, so called, gyrotropic current is calculated in zero frequency case as well in infrared frequency region. The static gyrotropic current yields negligibly small correction to the London magnetostatics in a superconductor without inversion center. Whereas the high frequency response produces the natural-optical activity revealed f.e. in the Kerr effect. The magnitude of the Kerr angle in infrared frequency region is proved to be in reasonable correspondence with recently reported observations of the Kerr effect in the pseudogap phase in several different high Tc materials.