[1] Xiangtan Univ, Natl Prov Lab Special Funct Thin Film Mat, Sch Mat Sci & Engn, Xiangtan 411105, Hunan, Peoples R China
[2] Ioffe Inst, 26 Politekhnicheskaya Str, St Petersburg 194021, Russia
[3] CERN, CH-1211 Geneva 23, Switzerland
[4] Vienna Univ Technol, Univ Ring 1, A-1010 Vienna, Austria
[5] Helsingin Yliopisto, Helsinki Inst Phys, Helsinki 200014, Finland