NbN/MgO/NbN edge-geometry tunnel junctions

Hunt, B. D.; LeDuc, H. G.; Cypher, S. R.; Stern, J. A.; Judas, A.
July 1989
Applied Physics Letters;7/3/1989, Vol. 55 Issue 1, p81
Academic Journal
We report the fabrication and low-frequency testing of the first edge-geometry NbN/MgO/NbN superconducting tunnel junctions. The use of an edge geometry allows very small junction areas to be obtained, while the all-NbN electrodes permit operation at 8–10 K with a potential maximum operating frequency above 1 THz. Edge definition in the base NbN film was accomplished utilizing Ar ion milling with an Al2O3 milling mask, followed by a lower energy ion cleaning step. This process has produced all-refractory-material tunnel junctions with areas as small as 0.1 μm2, resistance-area products less than 21 Ω μm2, and subgap to normal state resistance ratios larger than 18.


Related Articles

  • n-InAs/GaAs heterostructure superconducting weak links with Nb electrodes. Kleinsasser, A. W.; Jackson, T. N.; Pettit, G. D.; Schmid, H.; Woodall, J. M.; Kern, D. P. // Applied Physics Letters;12/22/1986, Vol. 49 Issue 25, p1741 

    We report on the fabrication and characterization of planar superconductor-normal-superconductor (SNS) weak links in which the normal region is deposited n-InAs. The InAs is part of a heterostructure consisting of 100 nm of n-InAs grown on an undoped GaAs buffer layer on a semi-insulating GaAs...

  • Transport and structural properties of the Ho1Ba2Cu3O9-δ superconductor. Lee, Sung-Ik; Golben, John P.; Song, Yi; Lee, Sang Young; Noh, Tae W.; Chen, Xiao-dong; Testa, Joe; Gaines, J. R.; Tettenhorst, Rodney T. // Applied Physics Letters;7/27/1987, Vol. 51 Issue 4, p282 

    The compound Ho1Ba2Cu3O9-δ has been found to be a high Tc superconductor. The onset of the superconducting transition is 88 K with zero resistance achieved at 87 K. The x-ray diffraction spectrum of this material shows it to be a single-phase perovskite similar to the Y1Ba2Cu3O9-δ compound...

  • Thulium barium copper oxide: A 90-K superconductor with a potential 1-MG upper critical field. Neumeier, J. J.; Dalichaouch, Y.; Ferreira, J. M.; Hake, R. R.; Lee, B. W.; Maple, M. B.; Torikachvili, M. S.; Yang, K. N.; Zhou, H. // Applied Physics Letters;8/3/1987, Vol. 51 Issue 5, p371 

    Upper critical magnetic fields Hc2(T) have been measured resistively for the high-temperature (Tc>=90 K) superconductors TmBa2Cu3O9-δ and YBa2Cu3O9-δ in applied magnetic fields H up to 9 T. If H at the resistive midpoint is defined as Hc2, then the upper critical field slopes (dHc2/dT)Tc...

  • Soft mode behavior in the orthorhombic to tetragonal transition in the high Tc superconductor YBa2Cu3O7-δ. Tallon, J. L.; Schuitema, A. H.; Tapp, N. E. // Applied Physics Letters;2/8/1988, Vol. 52 Issue 6, p507 

    The Young’s modulus and rigidity modulus of the high Tc superconductor YBa2Cu3O7-δ is measured from 300 to 1125 K using a 40-kHz ultrasonic resonant composite oscillator. Marked soft mode behavior occurs in both moduli in the vicinity of the orthorhombic to tetragonal transition, the...

  • Critical current enhancement in NbN/AlN multilayers. Murduck, J. M.; Capone, D. W.; Schuller, Ivan K.; Foner, S.; Ketterson, J. B. // Applied Physics Letters;2/8/1988, Vol. 52 Issue 6, p504 

    Measurements are presented of the critical current density, Jc, and parallel upper critical field, Hc2||, for the refractory superconductor/insulator multilayer system NbN/AlN. A dramatic increase in Jc, together with an increase of Hc2||, is observed with decreasing NbN layer thickness. The Jc...

  • Two-dimensional weak localization effects in high temperature superconductor Nd[sub 2-x]Ce[sub x]CuO[sub 4-δ]. Harus, G. I.; Ignatenkov, A. N.; Ponomarev, A. I.; Sabirzyanova, L. D.; Shelushinina, N. G.; Ivanov, A. A. // Journal of Experimental & Theoretical Physics;Nov99, Vol. 89 Issue 5, p933 

    A systematic study of the resistivity and Hall effect in single-crystal films Nd[sub 2-x]Ce[sub x]CuO[sub 4-δ] (0.12≤x≤0.20) is presented, with special emphasis on the low-temperature dependence of the normal state conductance. Two-dimensional weak localization effects are found...

  • Physics of weak/strong links and junctions in HTS. Halbritter, J. // AIP Conference Proceedings;2002, Vol. 614 Issue 1, p777 

    The major obstacles for HTS transport currents, both, dc- or rf-wise, are weak links appearing easily and rapidly in HTS-preparation or in HTS-growth. Weak links are runnel junctions showing reduced critical Josephson currents j[sub CJ](A/cm²), enhanced normal R[sub bn](Ωcm²), and...

  • The Instability Point H[sub s] of the Meissner State for Large-κ Superconductors. Ovchinnikov, Yu. N. // Journal of Experimental & Theoretical Physics;May2001, Vol. 92 Issue 5, p858 

    The critical field H[sub s] corresponding to the emergence of vortices in a superconductor without a threshold is found near the transition temperature and in the limit as T→0 for an arbitrary value of the depairing factor Γ. In superconductors of the second kind, this field value...

  • Low-temperature scanning laser microscopy of individual filaments extracted from (Bi, Pb)[sub 2]Sr[sub 2]Ca[sub 2]Cu[sub 3]O[sub 10+x] tapes. Sivakov, A. G.; Lukashenko, A. V.; Abraimov, D.; Mu¨ller, P.; Ustinov, A. V.; Leghissa, M. // Applied Physics Letters;5/1/2000, Vol. 76 Issue 18 

    The method of low-temperature scanning laser microscopy is applied to visualize the resistive state in individual superconducting filaments extracted from (Bi, Pb)[sub 2]Sr[sub 2]Ca[sub 2]Cu[sub 3]O[sub 10+x]/Ag tapes. This technique is capable of imaging the distributions of the critical...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics