A team of researchers led by Alan C. Seabaugh, professor of electrical engineering and associate director of the Center for Nano Science and Technology, has developed a new instrument capable of positioning vacuum-deposited metals, semiconductors, and dielectrics with nanometer-scale resolution. The instrument enables the formation of three-dimensional nanostructures, shown here, without organic resists and customized masks (traditional lithography). The piezoflexure-enabled nanofabrication (PEN) technique can produce features at the nanometer scale and allow for the clean characterization of surfaces near room temperature.

Funding for the instrument was provided by the Nanotechnology Exploratory Research and Major Research Instrument programs of the National Science Foundation, as well as the University’s Office of Research.

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Bernstein Named IEEE Fellow

Gary H. Bernstein, professor and associate chair of the Department of Electrical Engineering, has been named a fellow of the Institute for Electrical and Electronics Engineers (IEEE), “for contributions to techniques for fabricating nanoscale devices and circuits.”

Bernstein’s interests are in ULSI fabrication and related areas, including the experimental study of quantum-effect devices based on semiconductor and metal systems; digital integrated circuits based on resonant tunneling devices, which have been demonstrated to operate at speeds greater than 10 Ghz; and the reliability of deep submicron metal interconnects for future ULSI applications. He joins 14 current engineering faculty who also hold the rank of IEEE fellow.

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IEEE Recognizes Haenggi and Tabuada for Highly Accessed Papers

According to IEEE Xplore® — an online directory of technical literature in electrical engineering, computer science and engineering, and electronics, the paper authored by Assistant Professor Martin Haenggi titled “Routing in Ad Hoc Networks: A Case for Long Hops” was ranked 52 among the top 100 documents accessed in November 2005. It was originally published in the October 2005 issue of IEEE Communications Magazine.

ScienceDirect’s TOP 25 Hottest Articles cited Assistant Professor Paulo Tabuada’s paper titled “Bisimulation Relations for Dynamical, Control, and Hybrid Systems” as the sixth most read paper in Theoretical Computer Science. It was printed in the September 1, 2005, issue.

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Laneman Receives Recognition from NSF and Thompson

Assistant Professor J. Nicholas Laneman, has received the National Science Foundation’s (NSF) Early Career Development (CAREER) Award for his project proposal “Toward a Renaissance in Finite Blocklength Information Theory.”

Laneman is studying optimum blocklengths. Longer blocklengths lead to more reliable transmissions, but they also contribute to delays, which may be acceptable for some applications, such as e-mail or text messaging, but not for cell phone calls or video streaming. He and his students are testing for the optimum blocklengths of specific applications to balance the tension between reliable communication and tolerable delays.

In addition to directing the CAREER project, Laneman is also the principal investigator for the collaborative research project “Delay Constrained Multihop Transmission in Wireless Networks: Interaction of Coding, Channel Access, and Routing,” which is funded by the Theoretical Foundations program of the Computer and Information Science and Engineering division of the NSF. According to the NSF, the grant supporting this project was the largest among the 31 awards made by the program in 2005.

A paper Laneman co-authored with David Tse, professor of electrical engineering and computer sciences at the University of California at Berkeley, and Gregory W. Wornell, professor of electrical engineering and computer science at the Massachusetts Institute of Technology, “Cooperative Diversity in Wireless Networks: Efficient Protocols and Outage Behavior,” was also recently featured as one of the “New Hot Papers” by Thompson Essential Science Indicators. The paper was originally published in the December 2004 issue of IEEE Transactions on Information Theory.

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Multidisciplinary Team Demonstrates Magnetic Logic

Magnets are currently used in memory and data storage applications, however; they have not yet been used to perform logic functions. Researchers in the Center for Nano Science and Technology recently demonstrated magnetic quantum-dot cellular automata (QCA). Center Director Wolfgang Porod, the Freimann Professor of Electrical Engineering, and University researchers Alexandra Imre, Lili Ji, Alexei Orlov, and Professor Gary H. Bernstein, in conjunction with Gyorgy Csaba of the Institute for Nanoelectronics at the Technical University of Munich, applied magnetic systems to QCA implementations. In their demonstration nanomagnets hold information, and magnetic interactions execute logic functions.

One of the advantages of magnetic QCA is that it can operate at room temperatures, using little or no electricity. Magnetic QCA also leverages advances made by the magnetic-storage industry for patterned media and offers the potential of an all-magnetic information processing system.

Demonstrating the concept is the first step in the development of an all-magnetic system. It is important because current technology relies on traditional transistors, which are nearing their physical limits. “As we proceed, we would like to fabricate larger structures, beyond the single majority logic gate we demonstrated,” says Porod. “We would also like to realize electronic ways to set the input and to read the output.”

The concept for magnetic computing stemmed from QCA, a transistorless approach to computing which was pioneered at Notre Dame by Porod and Craig S. Lent, the Freimann Professor of Electrical Engineering. According to Porod, “The basic idea of magnetic QCA is the same as it was for electronic QCA, except that nanomagnets hold the information, and magnetic interactions are used to perform logic.”

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