Circular photogalvanic effect in CdSe nanowires at room temperature

Abstract

The anisotropy of Dresselhaus spin-orbit coupling (SOC) in cadmium selenide (CdSe) nanobelt and nanowire was studied by circular photogalvanic effect and it was demonstrated that the Dresselhuas SOC parameter is zero along [0001] crystallographic direction. The zero Dresselhaus SOC suppresses the spin relaxation and increases the spin diffusion length, which is beneficial to spin manipulation. To achieve a device structure with Rashba SOC presence and Dresselhaus SOC absence to manipulate spin degree of freedom, ionic liquid gate was applied on a nanowire grown along [0001] crystallographic direction, and Rashba SOC was induced as expected.