1. Temperature and field dependence of the intrinsic tunnelling structure in overdoped Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$
- Author
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Benseman, T. M., Cooper, J. R., and Balakrishnan, G.
- Subjects
Condensed Matter - Superconductivity - Abstract
We report intrinsic tunnelling data for mesa structures fabricated on three over- and optimally-doped $\rm{Bi_{2.15}Sr_{1.85}CaCu_{2}O_{8+\delta}}$ crystals with transition temperatures of 86-78~K and 0.16-0.19~holes per CuO$_2$ unit, for a wide range of temperature ($T$) and applied magnetic field ($H$), primarily focusing on one over-doped crystal(OD80). The differential conductance above the gap edge shows 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., Comment: 15 pages, 15 figures plus supplemental material, 1 table and 47 ASCII files with raw data. Corrected files for Fig. 12a
- Published
- 2015
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