Comparison of Intrinsic Josephson and SIS Tunneling Spectroscopy of Bi₂Sr₂CaCu₂O8+δ

Abstract

Tunneling spectroscopy measurements are reported on optimally-doped and overdoped Bi2Sr2Ca2Cu2O 8+δ single crystals. A novel point contact method is used to obtain superconductor-insulator-normal metal (SIN) and SIS break junctions as well as intrinsic Josephson junctions (IJJ) from nanoscale crystals. Three junction types are obtained on the same crystal to compare the quasiparticle peaks and higher bias dip/hump structures which have also been found in other surface probes such as scanning tunneling spectroscopy and angle-resolved photoemission spectroscopy. However, our IJJ quasiparticle spectra consistently reveal very sharp conductance peaks and no higher bias dip structures. The IJJ conductance peak voltage divided by the number of junctions in the stack consistently leads to a significant underestimate of Δ when compared to the single junction values. The comparison of the three methods suggests that the markedly different characteristics of IJJ are a consequence of nonequilibrium effects and are not intrinsic quasiparticle features.

Department(s)

Physics

Second Department

Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

Crystal growth; Crystallization; Electric conductance; Electron tunneling; High temperature applications; Photoemissive devices; Semiconducting bismuth compounds; Semiconductor doping; Spectroscopic analysis; Tunnel junctions; Intrinsic Josephson junctions (IJJ); Photoemission spectroscopy; SIS junctions; Tunneling spectroscopy; Josephson junction devices

International Standard Serial Number (ISSN)

1051-8223

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2005 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jun 2005

Link to Full Text

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