Conductance asymmetry in point-contacts on epitaxial thin films of Ba(Fe$_{0.92}$Co$_{0.08}$)$_2$As$_2$

Manan Mehta; Goutam Sheet; D. A. Dikin; S. Lee; C. W. Bark; J. Jiang; J. D. Weiss; E. E. Hellstrom; M. S. Rzchowski; C. B. Eom; V. Chandrasekhar

doi:10.1063/1.3460274

arXiv · 1005.1626

Conductance asymmetry in point-contacts on epitaxial thin films of Ba(Fe$_{0.92}$Co$_{0.08}$)$_2$As$_2$

Manan Mehta·Goutam Sheet·D. A. Dikin·S. Lee·C. W. Bark·J. Jiang·J. D. Weiss·E. E. Hellstrom·M. S. Rzchowski·C. B. Eom·V. Chandrasekhar

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Abstract

Point-contact spectroscopy is a powerful tool for probing superconductors. One of the most common observations in the point-contact spectra on the recently discovered ferropnictide superconductors is a large conductance asymmetry with respect to voltage across the point-contact. In this paper we show that the antisymmetric part of the point-contact spectrum between a silver tip and an epitaxial thin film of Ba(Fe$_{0.92}$Co$_{0.08}$)$_2$As$_2$ shows certain unique features. These features have an interesting evolution with increasing temperature up to a temperature that is 30% larger than the critical temperature $T_c$ of the superconductor. We argue that this evolution can be associated with the rich normal state properties of these materials.

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Manan Mehta, Goutam Sheet, D. A. Dikin, S. Lee, C. W. Bark, J. Jiang, J. D. Weiss, E. E. Hellstrom, M. S. Rzchowski, C. B. Eom, V. Chandrasekhar. 2010-06-14. Conductance asymmetry in point-contacts on epitaxial thin films of Ba(Fe$_{0.92}$Co$_{0.08}$)$_2$As$_2$. https://doi.org/10.1063/1.3460274

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