Carrier and Spin Dynamics in InSb- and InMnSb- Based Heterostructures

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

Non Technical In analogy with the early development of semiconductor electronics, there is now a rapidly growing interest in the science and engineering of low-dimensional magnetic and narrow gap semiconductors. Narrow gap and magnetic semiconductors have the potential to lead to revolutionary spintronic devices in which the spin degree of freedom in addition to the charge can be used and manipulated. The expected advantages using spin-based devices include increasing data processing speed and integration densities, decreasing electric power consumption, and nonvolatility. The focus of this project is to study unexplored optical and magneto-optical properties of InSb-based narrow gap heterostructures and ferromagnetic structures such as InMnSb, with an emphasis on charge and spin dynamics using laser spectroscopic techniques. The proposed activities will train undergraduate and graduate researchers in frontier scientific projects to educate next generation experts in semiconductor optics with broad knowledge in quantum optics, laser spectroscopy, and nanotechnology to prepare them for a productive and exciting future in the fast growing technological world. Technical: In light of the growing interest in spin-related phenomena and devices, there is now renewed interest in the science and engineering of narrow gap semiconductors such as InSb based heterostructures. Narrow gap semiconductors offer several scientifically unique features such as a small effective mass, a large g-factor, a high intrinsic mobility, and large spin-orbit coupling. In semiconductors with large spin-orbit interaction the coupling of electron spin polarization with electric fields or currents can provide new opportunities for spin manipulation in electronic and optoelectronic devices. The goal of this project is to study unexplored optical properties of InSb-based quantum wells and the newest member of III-V ferromagnetic structures, InMnSb, with an emphasis on dynamical aspects. The objectives in this project are to: understand charge/spin dynamics in narrow gap structures, probe the effect of magnetic impurities on the spin/charge dynamics, and develop concepts for spin based device applications. The approach at Virginia Tech is to employ ultrafast laser spectroscopy techniques, such as pump-probe and magneto-optical Kerr/Faraday effect to exploit the unique features in these structures. The proposed research work will train undergraduate and graduate researchers with a strong background in material science, laser spectroscopy, and nanoscience.