The investigation and control of spin dynamics in semiconductors using ultrafast optical methods

Over the last few years, researchers around the world have been pursuing a new direction for high-performance semiconductor technologies, including lasers, photonic devices, electronic logic, and even new computers using quantum information, that would all operate based on a quantum mechanical property of the electron called "spin". By virtue of this spin property, an electron acts as a tiny magnet, and spin-based semiconductor devices will work by controlling the magnet's direction. Since it takes significantly less energy to flip the electron spin direction than to physically move electrons around in semiconductors using their electrostatic charge, transistor logic based on spin would have much lower power consumption than traditional charge-based logic devices. A new class of semiconductors doped with magnetic impurities are now being developed in which electron spins can be aligned at will and controlled using light. These materials could allow logic and memory functions in our computers to be integrated, leading to a drastic simplification in the way that computers are built. Semiconductor quantum dots, which are tiny nanometer-sized pieces of one type of semiconductor embedded in another, provide us with a convenient way to isolate a single electron. In the future, the spins of electrons trapped in arrays of quantum dots may allow us to develop new highly-secure communication systems based on quantum information. The proposed funding will support research into novel semiconductor materials, including magnetic semiconductors and quantum dots, that show great promise for applications in the areas of spin-based semiconductor logic, photonics and quantum information. These materials will be studied using a special laser that produces short bursts of light. These pulses of light can be used to control the spin direction and to "read-out" this direction with extremely high time resolution. This world-class research program will promote growth of the high technology industry in Canada by providing the intellectual foundation and highly-skilled researchers and technicians for the development of cutting-edge spin-based technologies.