Semiconductor, heterostructures quantum control

Calculating the exact response of a semiconductor heterostructure to an ultrafast laser pulse poses a daunting challenge. Fortunately, several approximate methods have been developed that encompass most of the dominant physical effects. In this work a model Hamiltonian approach is adopted to make contact with previous advances in quantum control theory. This method can be systematically improved to obtain agreement with existing experimental results. One of the main goals of this research is to evaluate the validity of the model, and to discover the conditions under which it can be reliably applied. 

In semiconductors, PL originates from the radiative recombination of pho-toexcited electron-hole pairs. Their nonradiative lifetime is determined by both bulk and surface recombination. Therefore, the major problem in observing PL from semiconductor surfaces and interfaces is to minimize signals which arise from defects and impurities in the bulk. This can be achieved with an improvement in material quality by means of an epitaxial growth together with the fabrication of special structures, such as semiconductor heterostructures and quantum wells. The control of the epitaxial growth process allows one to vary the relative contribution of bulk and surface recombination independently of each other. 

Recently, much attention has been paid to the importance of the quantum function realized by micro- and mesoscopically controlled semiconductor heterostructures. Conducting polymer heterolayers, leading to a conducting polymer superlattice exhibiting quantum size effects, should take an important place in both novel electronic and optical devices. 

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