1. Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
2. Department of Thermal and Fluid Engineering, University of Twente, 7500 AE Enschede, The Netherlands
3. Asylum Research, Santa Barbara, California 93117, United States
4. IBM Almaden Research Center, San Jose, California 95120, United States
5. Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States