1. University of Alberta, Department of Electrical and Computer Engineering, Edmonton, Alberta T6G 2V4, Canada
2. Micralyne Inc., Edmonton, Alberta T6N 1E6, Canada
3. University of Alberta, Department of Electrical and Computer Engineering, Edmonton, Alberta T6G 2V4, CanadacNRC National Institute for Nanotechnology, Edmonton, Alberta T6G 2M9, Canada