Investigation on Rashba spin–orbit interactions in two dimension quantum array for thermal imaging applications

Abstract

In this work, we investigated the optical properties of a two dimensional quantum array using tight binding method in the presence of the Rashba spin–orbit (RSOI) interaction. The results show that ribbon array has sharp peaks with maximum absorption up to 70 (arb. units), at the energy of 95 meV with FHWM of 48 meV that can be used in thermal imaging applications. We have studied the effect of structural parameters like the shape of the array (square or ribbon), number of array sites, number of potential valleys and material on the absorption spectrum. The results show that with migrating from a square shape to ribbon, sharp peaks convert to smaller and larger peaks. Also, the effect of applied external parameters like electric and magnetic fields have been studied. For electrical field, absorption spectrum has symmetry with respect to the applied electrical axis Maximum absorption can be achieved when the electric field applied along vertical aside of the array. But, this symmetry has broken by means of the RSOI interaction and there is a critical angle, where absorption coefficient has maximum value. Also, there is a red and blue shift with applying an electrical and magnetic field that can be used for tuning absorption in the desired wavelength. These facts can help experimentalist to design their desired thermal detector.