POINT CONTACT TUNNELING STUDIES ON CERAMIC YBCO WITH SCANNING TUNNELING MICROSCOPE TIPS

被引：3

作者：

SRIKANTH, H

RAJESWARI, M

RAYCHAUDHURI, AK

机构：

[1] Department of Physics, Indian Institute of Science, Bangalore

来源：

PRAMANA-JOURNAL OF PHYSICS | 1991年 / 36卷 / 02期

关键词：

POINT CONTACT; TUNNELING; SUPERCONDUCTING GAP; OXIDE SUPERCONDUCTORS; SCANNING TUNNELING MICROSCOPE;

D O I：

10.1007/BF02845706

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

A detailed study of point contact tunnelling into ceramic YBCO with electrochemically etched tips of Pt, Nb and W is reported. The superconducting gap parameter (DELTA) has been extracted from I - V and dI/dV - V curves using various procedures. Our results indicate a gap value of about 20 meV. We observe that the zero bias conductance is strongly dependent on the junction resistance. The normal state conductance varies linearly with bias voltage and the conductance curves are asymmetric with respect to polarity of the bias voltage. With contacts of very high junction resistance, we observe G(0)/G(100 mV) has a value as low as 1/6. This may be the lowest value reported so far.

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页码：207 / 219

页数：13

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