David D. Awschalom
Professor of Physics
Director, UC Center for Spintronics and Quantum Computation
 

There is a growing interest in the use of spins in semiconductor quantum
structures as a medium for the manipulation and storage of classical and
quantum information ("spintronics").  Femtosecond-resolved optical
experiments reveal a remarkable resistance of quantum electron spin states to environmental
decoherence in a variety of semiconductors. Spin lifetimes can exceed hundreds of
nanoseconds and spin packets can be transported over a hundred microns in some of these
systems. Moreover, interfaces are surprisingly permeable to the flow of spin
information over a broad range of temperatures, where regional boundaries
may be used to control the resulting spin coherent phase. In addition,
periodic excitation of the electronic spin system can be used to resonantly
operate on the nuclear spins of a semiconductor host and to detect
associated changes in the nuclear magnetization, thereby demonstrating
all-optical nuclear magnetic resonance (NMR). This technique allows for
sensitive and spatially selective NMR in single nanostructures, therein
serving as a basis for the coherent manipulation of nuclei in solids.