We present the results of point-contact spectroscopy measurements on high-quality epitaxial MgB2 thin films with injected current along the c-axis. The temperature and field dependences of π-band properties with the ...We present the results of point-contact spectroscopy measurements on high-quality epitaxial MgB2 thin films with injected current along the c-axis. The temperature and field dependences of π-band properties with the field parallel to （HⅡ） or perpendicular to （H⊥） the c-axis are investigated in detail. When a magnetic field is applied, either parallel or perpendicular to the c-axis, the density of the quasiparticle state （DOS） of the π-band proliferates quickly with increasing field, while the gap amplitude of the π-band decreases slowly, which is different from the recent theoretical calculations, showing a field dependent competition between the interband scattering and the pair-breaking effects.展开更多
基金Supported by the National Science Foundation of China, the National Basic Research Programme of China under Grant Nos 2006CB601000, 2006CB921802 and 2006CB921300, and the Knowledge Innovation Project of Chinese Academy of Sciences, the International Team on Superconductivity and Novel Electronic Materials （ITSNEM） of Chinese Academy of Sciences, the National Natural Science Foundation of China under Grant Nos DMR-0306746 （XXX）, DMR-0405502 （QL） and DMR-0514592 （ZKL and XXX）, and the ONR under Grant No N00014-00-1-0294 （XXX）.
文摘We present the results of point-contact spectroscopy measurements on high-quality epitaxial MgB2 thin films with injected current along the c-axis. The temperature and field dependences of π-band properties with the field parallel to （HⅡ） or perpendicular to （H⊥） the c-axis are investigated in detail. When a magnetic field is applied, either parallel or perpendicular to the c-axis, the density of the quasiparticle state （DOS） of the π-band proliferates quickly with increasing field, while the gap amplitude of the π-band decreases slowly, which is different from the recent theoretical calculations, showing a field dependent competition between the interband scattering and the pair-breaking effects.
