1. Department of Applied Physics, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
2. Key Laboratory of Instrumentation Science and Dynamic Measurement, School of Instrument and Electronics, North University of China, Taiyuan, Shanxi 030051, China
3. CCMS, Institute of Physics, Slovak Academy of Sciences, 84511 Bratislava, Slovakia
4. Department of Physics, School of Natural and Mathematical Science, King’s College London, The Strand, London WC2R 2LS, U.K.
5. Institute of Informatics, Slovak Academy of Sciences, 845 07 Bratislava, Slovakia
6. Department of Natural Sciences, University of Ss. Cyril and Methodius, 917 01 Trnava, Slovakia