COMPUTATIONAL RESEARCH in BOSTON and BEYOND (CRIBB)

Over the past 50 years, the continual miniaturization of semiconducting structures comprising electronic circuits resulted in a rapid increase of computational power with very few fundamental changes in component design. However, we are quickly reaching a limit where the current production designs of transistors and logic gates will no longer be able to scale down to smaller sizes without serious changes in performance due to quantum effects such as tunneling and interference. To facilitate the further development of information processing technologies, we must now find new ways of storing and manipulating information in "mesoscopic systems," where both classical and quantum mechanical behaviors can arise.

In the first part of this talk I will introduce the basic physics of the Field Effect Transistor (FET) and describe the onset of quantum effects as such devices are miniaturized down to the mesoscale. Although such quantum effects are considered to be a nuisance to CMOS chip designers, many useful solid-state devices based on quantum mechanical principles can now be fabricated and studied. To illustrate this point, in the second part of this talk I will describe the interesting coupled dynamics of electron and nuclear spins that arises due to DC transport through quantum dots in the so-called spin blockade regime.