Transport and Noise Properties of sub-100-nm Planar Nb Josephson Junctions with Metallic Hf-Ti Barriers for nano-SQUID Applications

Morosh, V. ; Linek, J. ; Muller, B. ; Martinez-Perez, M.J. (Universidad de Zaragoza) ; Wolter, S. ; Weimann, T. ; Beyer, J. ; Schurig, T. ; Kieler, O. ; Zorin, A.B. ; Kleiner, R. ; Koelle, D.

Resumen: We analyze electric transport and noise properties at 4.2 K of self-shunted superconductor-normal metal-superconductor (SNS) sandwich-type Josephson junctions, comprising Nb as the superconductor and Hf-Ti as the normal conducting material, with lateral dimensions down to approximately 80 nm. The junctions are fabricated with an optimized multilayer Nb technology based on nanopatterning by electron-beam lithography and chemical-mechanical polishing. The dependence of transport properties on the junction geometry (lateral size and barrier thickness d(Hf-Ti)) is studied, yielding a characteristic voltage V-c up to approximately 100 mu V for the smallest d(Hf-Ti) = 17 nm. The observed small hysteresis in the current-voltage curves of devices with high V-c and large size can be attributed to self-heating of the junctions and fitted with an extended version of the resistively shunted junction model. Measurements of voltage noise of single junctions are consistent with the model including self-heating effects. The potential of our technology for further miniaturization of nanoscale superconducting quantum interference devices and for the improvement of their performance is discussed.

Idioma: Inglés

DOI: 10.1103/PhysRevApplied.14.054072

Año: 2020

Publicado en: Physical Review Applied 14, 5 (2020), 054072 [12 pp]
ISSN: 2331-7019

Factor impacto JCR: 4.985 (2020)

Categ. JCR: PHYSICS, APPLIED rank: 36 / 160 = 0.225 (2020) - Q1 - T1

Factor impacto SCIMAGO: 1.883 - Physics and Astronomy (miscellaneous) (Q1)

Financiación: info:eu-repo/grantAgreement/EUR/COST-Action/CA16218

Tipo y forma: Article (Published version)

Área (Departamento): Área Física Materia Condensada (Dpto. Física Materia Condensa.)