1. Electrical Engineering, Stanford University, Stanford, California 94305, United States
2. Hewlett-Packard Laboratories, 1501 Page Mill Road, Palo Alto, California 94304, United States
3. IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120, United States
4. Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, United States
5. Material Science and Engineering, Stanford University, Stanford, California 94305, United States