Nanospintronics with quantum dots

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An electron has charge and spin. Exploiting the electron's charge in semiconductor devices led to the 20th century information revolution. This program aims at contributing toward global efforts in exploiting electron spin at the nanoscale. Electron spin is a quantum object and has potential use in devices operating according to quantum, instead of classical, mechanics. These quantum devices require localising, controlling and manipulating electron spins at the nanoscale. This can be accomplished using nanoscale semiconductor structures, semiconductor quantum dots. Two main avenues will be pursued. In the first approach the theory of lateral quantum dots (field effect transistors so small that each transistor contains just one electron spin) will be developed. Such theory will allow the exploration of these artificial molecules with a single spin each as small quantum processors, precursors of solid state computers. Once such processors are constructed and information is processed, it will need to be stored. This requires development of nanoscale memory elements embedded in a semiconductor. The smallest memory element we can imagine is a single magnetic ion. In the second part of the project we will focus on developing a theory of semiconductor nanostructures containing a controlled number of magnetic ions. The development of control over individual spins at the nanoscale, nano-spintronics, may potentially lead to low power devices, to quantum information devices, and to memory devices based on magnetic moments of individual magnetic ions.