Point contact tunnelling studies on ceramic YBCO with scanning tunnelling microscope tips

Srikanth, H and Rajeswari, M and Raychaudhuri, AK (1991) Point contact tunnelling studies on ceramic YBCO with scanning tunnelling microscope tips. In: Pramana, 36 (2). pp. 207-219.

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Abstract

A detailed study of point contact tunnelling into ceramic YBCO with electrocliemically 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 20meV. 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(O)/G(l00mV) has a value as low as 1/6. This may be the lowest value reported so far.

Item Type:	Journal Article
Publication:	Pramana
Publisher:	Indian Academy of Science
Additional Information:	Copyright of this article belongs to Indian Academy of Sciences.
Keywords:	Point contact; tunnelling; superconducting gap; oxide superconductors; scanning tunnelling microscope.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	11 Mar 2008
Last Modified:	19 Sep 2010 04:43
URI:	http://eprints.iisc.ac.in/id/eprint/13381

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