1. Electrical and Computer Engineering Department, University of Virginia, Charlottesville, Virginia 22904, USA
2. Synopsys Inc, 455 N Mary Ave, Sunnyvale, California 94085, USA
3. Microelectronics Research Center, University of Texas, Austin, Texas 78758, USA
4. Department of Physics, University of Virginia, Charlottesville, Virginia 22904, USA
5. Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22904, USA