Effects of Spin Orbit Interaction on Optical Properties for Quantum Dot and Quantum Wire

Introduction

In recent times, remarkable progress in technology has been made, enabling the production of semiconductor structures of nanometer size. Semiconductor nanostructures have a large potential for applications in nano- and optoelectronics (Prinz, 1998; Bandyopadhyay, 2012; Kumar et al. 2013). They are different from natural atoms on the account of tunability of their energy spectrum by manipulating their size and geometry. Due to these features they are considered to be viable candidates for the applications in quantum optoelectronic devices which provides an interface between quantum bits and quantum optics and can perform quantum information processing (Banerjee & Charkavorty, 2002; Kumar et al. 2013). In this chapter, we are focusing on two nanostructures, quantum dot & quantum wire.

Among low dimensional semiconductor structures, quantum dots have drawn considerable interest for their appealing potential technological applications. The confinement of these structures into low dimension leads to the formation of discrete energy levels (subbands) which results in drastic change in absorption spectra and evolution of many novel properties. Quantum wires of all these structures have shown remarkable physical properties for finding applicability in future technologies like conducting nanowire in quantum computing devices (Banerjee & Charkavorty, 2002). They can be grown into desired radius using numerous semiconductor materials by different physical methods (Law et al. 2004; Zaitsey et al. 2000).

The nonlinear properties such as optical absorption and refractive index changes in these low dimensional structures have attracted much attention because of having high potentiality for device applications in photodetectors (Miller, 1991), far-infrared laser amplifiers (Kazarinov & Suris, 1971) and high speed electro-optical modulators (Hood, 1988). Recently, there has been significant research on semiconductor quantum dot (QD) and quantum wire (QW) especially the experimental and theoretical investigation of magnetic field on their optical properties (Okano at al. 2012; Gharaati & Khordad, 2012; Khordad, 2013). Further, the energy spectrum tune-ability by the confinement potential and magnetic fields in these stuctures have made them very strong candidates for study of linear and nonlinear properties for device applications and are extensively investigated (Zhang & Yao, 2011; Sugaya at al. 2005; Datta & Das, 1990; Schliemann at al. 2003).