Temperature and field dependence of the intrinsic tunnelling structure in overdoped Bi2Sr2CaCu2O8F8+delta

Article

关键词: T-C SUPERCONDUCTORS;    DENSITY-WAVE ORDER;    QUASI-PARTICLE;    VORTEX STATE;    BI2SR2CACU2O8+DELTA;    SPECTROSCOPY;    PSEUDOGAP;    TRANSPORT;    HEAT;    GAP;   

DOI  :  10.1103/PhysRevB.98.014507

来源: SCIE

【 摘 要 】

We report intrinsic tunneling data for mesa structures fabricated on three over- and optimally-doped Bi2.15Sr1.85CaCu2O8+delta crystals with transition temperatures of 86-78 K and 0.16-0.19 holes per CuO2 unit, for a wide range of temperature (T) and applied magnetic field (H), primarily focusing on one overdoped crystal (OD80). The differential conductance above the gap edge shows a clear dip structure which is highly suggestive of strong coupling to a narrow boson mode. Data below the gap edge suggest that tunnelling is weaker near the nodes of the d-wave gap and give clear evidence for strong T-dependent pair breaking. These findings could help theorists make a detailed Eliashberg analysis and thereby contribute towards understanding the pairing mechanism. We show that for our OD80 crystal the gap above T-c, although large, is reasonably consistent with the theory of superconducting fluctuations.

【 授权许可】

Free