MIT Department of Electrical Engineering & Computer Science

SPECIAL SEMINAR

Monday, February 27, 1995
Marlar Lounge, Room 37-252

Refreshements at 1:45 PM
Talk at 2:00 PM

Wave-Vector-Induced Collective Excitations in the Quantum Hall Regime

Dr. Lydia L. Sohn
AT&T Bell Laboratories

Because of recent advances in nanofabrication technology, it is now possible to create (with great control and precision) devices so small (approximately 800 Angstroms squared) that their behavior is solely governed by the charge of a single electron. Examples of such devices include single-electron turnstiles and pumps, arrays of Josephson junctions, and quantum dots. Each of these has proved to be a very rich and intriguing physical system from which we have gained novel insight into mesoscopic phenomena. More importantly, however, each has demonstrated the potential for metrological applications such as a highly accurate electrometer and current standard.

This talk will present an overview of the current nanofabrication techniques that have enabled the examination of Josephson junction arrays and 2D electron systems at previously unattainable length scales (approximately 600 Angstroms squared). In addition, the investigator will present her most recent efforts to develop atomic force microscope lithography. Such lithography is capable of producing structures with a characteristic length scale of less than 200 Angstroms, thus opening the way towards discovering new quantum phenomena and novel device applications.