February 2, 2001

Colloquium Topic: Heterostructures and Spintronics

Traditional electronic devices are based on the transport and storage of electronic charges. Magnetic heterostructures provide opportunities for the exploration of new physical phenomena and the development of spintronic devices where both charge and spin of electrons are exploited. The basic heterostructures of materials with high spin polarization that enable new devices such as spin-valve giant magnetoresistance (GMR) read-heads and magnetic random access memory (MRAM) will be described. The prospects of the so called ³half-metals² and the measurement of their 100% spin polarization will be discussed. Finally, the unusual MR properties of Bi thin films and its potential role in spin transport will be described.

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Colloquium Speaker: Chia-Ling Chien

Professor Chia-Ling Chien received his B.S. in physics from Tunghai University, Taiwan, and M.S. and Ph.D. in physics from Carnegie-Mellon University. He came to the Johns Hopkins University as a postdoctoral fellow in 1973, joined the faculty in 1976 and became a professor of physics in 1983. Currently, he is the Director of the Materials Research Science and Engineering Center on nanostructured materials funded by the NSF. His main research interests are fabrication and experimental studies of structural, electronic, magnetic, transport, and superconducting properties of nanostructured materials. He is a fellow of the American Physical Society and an Honorary Professor at Nanjing University of China. Professor Chien has authored or co-authored nearly 300 scientific papers.