Computer Systems Laboratory Colloquium

4:15PM, Wednesday, October 24, 2001
NEC Auditorium, Gates Computer Science Building B03

Multifunctional Spintronics and Quantum Information Processing in Semiconductors

David D. Awschalom
University of California - Santa Barbara
About the talk:

There is a growing interest in the use of electronic and nuclear spin in semiconductor nanostructures as a medium for the manipulation and storage of classical and quantum information. Recent experiments reveal a remarkable resilience of electronic spin states to environmental decoherence in a variety of bulk semiconductors, heterostructures, and quantum dots. Spin lifetimes can exceed hundreds of nanoseconds, enabling the transport of coherent spin packets over hundreds of microns. Furthermore, coherent spin information can flow across interfaces of dissimilar materials in engineered structures. The interfaces appear surprisingly permeable over a broad range of temperatures, and the transport of spin information can be controlled with both electric and magnetic fields. Nuclear spin lifetimes, which are orders of magnitude longer than those of electrons, may ultimately enable long-term storage of quantum information. Local manipulation of nuclei can be achieved by periodic optical excitation of precessing electrons that surround the atomic sites. Changes in the magnetization of resonantly tipped nuclei demonstrate the ability to perform all-optical nuclear magnetic resonance (NMR). This sensitive and spatially selective NMR technique may serve as a basis for the coherent manipulation of nuclear moments at the atomic level. Finally, the capability to integrate ferromagnetism within semiconductor nanostructures may create new schemes for operating on electron and nuclear spins. These results point towards opportunities to combine logic and storage for novel multifunctional quantum mechanical electronics that incorporate electronics, magnetics, and photonics.

About the speaker:

David D. Awschalom received his undergraduate degree in physics from the University of Illinois at Urbana-Champaign, and his Ph.D. in experimental physics from Cornell University. He was a Research Staff member and Manager of the Nonequilibrium Physics Department at the IBM Watson Research Center in Yorktown Heights, NY. In 1991 he joined the University of California - Santa Barbara as a Professor of Physics, and is presently Director of the UC Center for Spintronics and Quantum Computation. His group has active research activities in optical and magnetic interactions in semiconductor quantum structures, spin dynamics and coherence in condensed matter systems, macroscopic quantum phenomena in nanometer-scale magnets, and implementations of quantum computation in the solid state. He has developed a variety of femtosecond-resolved spatiotemporal magneto-optical spectroscopies and micromagnetic sensing techniques aimed at exploring charge and spin motion in the quantum domain. This research has been presented in over 300 invited lectures and in nearly 200 scientific publications. Professor Awschalom received an IBM Outstanding Innovation Award, the Outstanding Investigator Prize from the Materials Research Society, and was the Institute of Physics Wohlfarth Prize Lecturer. Dr. Awschalom is a member of the American Association for the Advancement of Science, the Materials Research Society, and is a Fellow of the American Physical Society.

Contact information:

David D. Awschalom
Department of Physics
University of California
Santa Barbara, CA 93106
(805) 893-2121
(805) 893-4170