Abstract : In this talk I will begin with the effect of spin-orbit interaction on electron transport in nanowires at the mesoscopic regime and introduce how energy bands get modified due to inversion asymmetry in a material. Finally I will show that spin momentum of light can be sensitive to externally perturbed energy band modification due to certain geometry of nanostructure. This work reveals the role of the surface states in the generation of chirality-dependent photocurrents in silicon with a purely orbital-based mechanism, and also opens up possibilities of engineering new functionalities in silicon that can be integrated with conventional electronics.