1. Department of Applied Physics; Stanford University, Geballe Laboratory for Advanced Materials; 476 Lomita Mall Stanford CA 94305 USA
2. Department of Electrical Engineering; Stanford University, Geballe Laboratory for Advanced Materials; 476 Lomita Mall Stanford CA 94305 USA
3. Department of Physics; Stanford University, Geballe Laboratory for Advanced Materials; 476 Lomita Mall Stanford CA 94305 USA
4. Department of Materials Science and Engineering; Stanford University, Geballe Laboratory for Advanced Materials; 476 Lomita Mall Stanford CA 94305 USA