1. Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, USA
2. Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, California 90095, USA
3. Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720, USA
4. Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA
5. Advanced Light Source, Lawrence Berkeley National Lab, Berkeley, California 94720, USA
6. California NanoSystems Institute, Los Angeles, California 90095, USA