# Magneto-optical effects in the Landau level manifold of 2D lattices with spin-orbit interaction

## TL;DR

This paper develops a method to analyze the magneto-optical response of silicene, a 2D material with strong spin-orbit interaction, showing how electric and magnetic tuning can enhance effects like Faraday rotation and Kerr effect.

## Contribution

A general analytical approach for calculating valley and spin polarized magneto-optical effects in silicene under various external fields.

## Key findings

- Large Faraday rotation and Kerr effect can be achieved with electric and magnetic tuning.
- Analytic expressions for valley and spin polarized responses in the terahertz regime.
- Magneto-optical effects are highly tunable in silicene and similar 2D materials.

## Abstract

Silicene is a competitive and promising 2D material, possessing interesting topological, electronic and optical properties. The presence of strong spin orbit interaction in silicene and its analogues, germanene and tinene, leads to the opening of a gap in the energy spectrum and spin-splitting of the bands in each valley. We develop a general method to determine the magneto-optic response of silicene, when a Gaussian beam is incident on silicene grown on a dielectric substrate in the presence of a static magnetic field. We use a semiclassical treatment of silicene monolayer to describe the Faraday rotation (FR) and Magneto-optical Kerr effect (MOKE) using a general model for beam propagation. The response can be modulated both electrically and magnetically. We derive analytic expressions for valley and spin polarized FR and MOKE for arbitrary polarization of incident light in the terahertz regime. We demonstrate that large FR and MOKE can be achieved by tuning the electric field, magnetic fields and chemical potential in these fascinating 2D materials. Implications for novel valleytronic experiments are also discussed.