1. Department of Energy Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
2. Ioffe Physical-Technical Institute, 26 Politekhnicheskaya, Saint Petersburg 194021, Russia
3. Institute of Materials Science, Swiss Federal Institute of Technology (EPFL), Lausanne CH-1015, Switzerland
4. Institute of Electromagnetic Fields, ETH Zurich, Zurich CH-8092, Switzerland
5. Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano 20133, Italy