High-Quality Planar high-T$_c$ Josephson Junctions

N. Bergeal , X. Grison , J. Lesueur , G. Faini , M. Aprili (1) , J. P. Contour

1 CSNSM - Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse

Reproducible high-T$_c$ Josephson junctions have been made in a rather simple two-step process using ion irradiation. A microbridge (1 to 5 $\mu$m wide) is firstly designed by ion irradiating a c-axis-oriented YBa$_2$Cu$_3$O$_7_-\delta$ film through a gold mask such as the non-protected part becomes insulating. A lower T$_c$ part is then defined within the bridge by irradiating with a much lower fluence through a narrow slit (20 nm) opened in a standard electronic photoresist. These planar junctions, whose settings can be finely tuned, exhibit reproducible and nearly ideal Josephson characteristics. This process can be used to produce complex Josephson circuits.

Mots clés: high-temperature superconductors; Josephson effect; superconducting junction devices; ion beam effects; yttrium compounds; barium compounds; superconducting thin films; superconducting transition temperature

Domaines: Supraconductivité [cond-mat.supr-con]

N. Bergeal, X. Grison, J. Lesueur, G. Faini, M. Aprili, et al.. High-Quality Planar high-T$_c$ Josephson Junctions. Applied Physics Letters, 2005, 87, pp.102502. ⟨10.1063/1.2037206⟩. ⟨in2p3-00024675⟩