# Strong anisotropic optical conductivity in two dimensional puckered structures: The role of Rashba effect

## TL;DR

This paper investigates the anisotropic optical conductivity in 2D puckered structures influenced by Rashba effects, revealing how external fields and anisotropy affect optical absorption and spintronic parameters.

## Contribution

It provides an analytical model for the anisotropic optical conductivity in 2D systems with Rashba effects, highlighting the impact of anisotropy and external fields on optical properties.

## Key findings

- Optical absorption spectrum is highly anisotropic and sensitive to system parameters.
- Peak height increases with effective mass anisotropy ratio.
- Peak width broadens with increased Rashba interaction and density of states.

## Abstract

We calculate the optical conductivity of an anisotropic two-dimensional system with Rashba spin-flip excitation within the Kubo formalism. We show that the anisotropic Rashba effect caused by an external field changes significantly the magnitude of the spin splitting. Furthermore, we obtain an analytical expression for the longitudinal optical conductivity associated with inter-band transitions as a function of the frequency for an arbitrary polarization angle. We find that the diagonal components of the optical conductivity tensor are direction-dependent and the spectrum of optical absorption is strongly anisotropic with an absorption window. The height and width of this absorption window are very sensitive to the system anisotropy. While the height of absorption peak increases with increasing effective mass anisotropy ratio, the peak intensity is larger when the light polarization is along the armchair direction. Moreover, the absorption peak width becomes broader as the density of state mass or Rashba interaction is enhanced. These features can be used to determine parameters relevant for spintronics through the optical absorption spectrum.