中国物理B ›› 2013, Vol. 22 ›› Issue (5): 57402-057402.doi: 10.1088/1674-1056/22/5/057402

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Energy gap suppression and excess current in Tl2Ba2CaCu2O8 intrinsic Josephson junctions

王培, 解伟, 胡磊, 刘欣, 赵新杰, 何明, 季鲁, 张旭, 阎少林   

  1. Department of Electronics, Nankai University, Tianjin 300071, China
  • 收稿日期:2012-11-27 修回日期:2012-12-21 出版日期:2013-04-01 发布日期:2013-04-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61176119, 61171028, 51002081, and 61101018) and the Fundamental Research Funds for the Central Universities of China.

Energy gap suppression and excess current in Tl2Ba2CaCu2O8 intrinsic Josephson junctions

Wang Pei (王培), Xie Wei (解伟), Hu Lei (胡磊), Liu Xin (刘欣), Zhao Xin-Jie (赵新杰), He Ming (何明), Ji Lu (季鲁), Zhang Xu (张旭), Yan Shao-Lin (阎少林)   

  1. Department of Electronics, Nankai University, Tianjin 300071, China
  • Received:2012-11-27 Revised:2012-12-21 Online:2013-04-01 Published:2013-04-01
  • Contact: He Ming E-mail:heming@nankai.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61176119, 61171028, 51002081, and 61101018) and the Fundamental Research Funds for the Central Universities of China.

摘要: Intrinsic Josephson junctions in misaligned Tl2Ba2CaCu2O8 thin film were fabricated on LaAlO3 substrate. The temperature dependence of the critical current is investigated around liquid nitrogen temperature. In the current voltage characteristic, large voltage jump and free of resistive branch are observed, which shows good consistency with the intrinsic Josephson junctions. By analyzing the large gap voltage in the curve, great suppression of the energy gap is found. Through discussing the temperature dependence of the gap voltage in liquid nitrogen temperature, it is showed that this phenomenon can be caused by the nonequilibrium quasiparticle injection. The temperature influence on the excess current also confirms the nonequlibrium effect.

关键词: intrinsic Josephson junctions, current voltage characteristics, energy gap, excess current

Abstract: Intrinsic Josephson junctions in misaligned Tl2Ba2CaCu2O8 thin film were fabricated on LaAlO3 substrate. The temperature dependence of the critical current is investigated around liquid nitrogen temperature. In the current voltage characteristic, large voltage jump and free of resistive branch are observed, which shows good consistency with the intrinsic Josephson junctions. By analyzing the large gap voltage in the curve, great suppression of the energy gap is found. Through discussing the temperature dependence of the gap voltage in liquid nitrogen temperature, it is showed that this phenomenon can be caused by the nonequilibrium quasiparticle injection. The temperature influence on the excess current also confirms the nonequlibrium effect.

Key words: intrinsic Josephson junctions, current voltage characteristics, energy gap, excess current

中图分类号:  (Cuprate superconductors)

  • 74.72.-h
74.50.+r (Tunneling phenomena; Josephson effects)