Carrier and Spin Dynamics in Narrow Gap Multi Quantum Well Structures

We studied carrier/spin dynamics in several $InSb/Al_{x}In_{1-x}Sb$ multiple-quantum well structures using several time resolved differential transmission schemes in the mid-infrared. Our results demonstrate the unique and complex dynamics in InSb heterostructures that can be important for electronic and optoelectronic devices. We present experimental observations and compare them with theoretical calculations. Calculations are based on the 8-band Pidgeon-Brown model generalized to include confinement potential as well as pseudomorphic strain. Optical properties are calculated within the golden rule approximation and compared with one and two color, time-resolved pump-probe differential transmission.