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In this paper we extend our earlier analysis of the novel Josephson effect in triplet superconductor--ferromagnet--triplet superconductor (TFT) junctions [B. Kastening \emph{et al.}, Phys. Rev. Lett. {\bf{96}}, 047009 (2006)]. In our more…

Superconductivity · Physics 2009-01-26 P. M. R. Brydon , Boris Kastening , Dirk K. Morr , Dirk Manske

Fabrication of sub-micron Josephson junctions is demonstrated using standard processing techniques for high-coherence, superconducting qubits. These junctions are made in two separate lithography steps with normal-angle evaporation. Most…

Superconductivity · Physics 2017-08-02 X. Wu , J. L. Long , H. S. Ku , R. E. Lake , M. Bal , D. P. Pappas

Atomic Layer Deposition (ALD) is a promising technique for producing Josephson junctions (JJs) with lower defect densities for qubit applications. A key problem with using ALD for JJs is the interfacial layer (IL) that develops underneath…

Superconductivity · Physics 2014-08-14 Alan J. Elliot , Chunrui Ma , Rongtao Lu , Melisa Xin , Siyuan Han , Judy Z. Wu , Ridwan Sakidja , Haifeng Yu

Superconducting qubits in today's quantum processing units are typically fabricated with angle-evaporated aluminum--aluminum-oxide--aluminum Josephson junctions. However, there is an urgent need to overcome the limited reproducibility of…

Superconducting qubit fabrication innovations continue to be explored to achieve higher performance. Despite improvements to base layer fabrication and processing, resist-based Josephson junction (JJ) schemes have largely remained…

Quantum Physics · Physics 2026-05-18 Tathagata Banerjee , Stephen Daniel Funni , Saswata Roy , Judy J. Cha , Valla Fatemi

Josephson junction transistors and 50-junction arrays with linear junction dimensions from 200 nm down to 70 nm were fabricated from standard Nb/AlOx/Nb trilayers. The fabrication process includes electron beam lithography, dry etching,…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 R. Dolata , H. Scherer , A. B. Zorin , J. Niemeyer

We present a structure and a fabrication method for superconducting tunnel junctions down to the dimensions of 200 nm using i-line UV lithography. The key element is a side-wall-passivating spacer structure (SWAPS) which is shaped for…

Josephson junctions are the key components used in superconducting qubits for quantum computing. The advancement of quantum computing is limited by a lack of stability and reproducibility of qubits which ultimately originates in the…

Mesoscale and Nanoscale Physics · Physics 2024-06-26 K. Bayros , M. J. Cyster , J. S. Smith , J. H. Cole

Shadow evaporation is commonly used to micro-fabricate the key element of superconducting qubits - the Josephson junction. However, in conventional two-angle deposition circuit topology, unwanted stray Josephson junctions are created which…

By scanning with a $30\, \mathrm{keV}$ focused He ion beam (He-FIB) across YBa$_2$Cu$_3$O$_7$ (YBCO) thin film microbridges, we create Josephson barriers with critical current density $j_\mathrm{c}$ adjustable by irradiation dose $D$. The…

Superconductivity · Physics 2019-04-30 B. Müller , M. Karrer , F. Limberger , M. Becker , B. Schröppel , C. J. Burkhardt , R. Kleiner , E. Goldobin , D. Koelle

High quality Nb-based superconductor-insulator-superconductor (SIS) junctions with Al oxide (AlO$_x$) tunnel barriers grown from Al overlayers are widely reported in the literature. However, the thin barriers required for high critical…

The structural and nanochemical properties of thin $AlO_x$ layers are decisive for the performance of advanced electronic devices. For example, they are frequently used as tunnel barriers in Josephson junction-based superconducting devices.…

Materials Science · Physics 2019-11-27 S. Fritz , L. Radtke , R. Schneider , M. Luysberg , M. Weides , D. Gerthsen

We have fabricated and characterized asymmetric gap-engineered junctions and transmon devices. To create Josephson junctions with asymmetric gaps, Ti was used to proximitize and lower the superconducting gap of the Al counter-electrode. DC…

Decoherence remains a critical obstacle to achieving high-fidelity, scalable superconducting qubits, with the tunnel barrier of Josephson junctions a key source of loss. Here we apply resonant X-ray reflectivity to non-destructively probe…

We have developed a novel fabrication process for ultra-small, full-epitaxial NbN Josephson junctions on a silicon (Si) substrate. A full-epitaxial NbN/AlN/NbN tri-layer was grown on a Si (100) wafer with a (200)-oriented TiN buffer layer.…

Superconductivity · Physics 2020-12-02 Wei Qiu , Hirotaka Terai

We have developed a novel Josephson junction geometry with minimal volume of lossy isolation dielectric, being suitable for higher quality trilayer junctions implemented in qubits. The junctions are based on in-situ deposited trilayers with…

In an in-situ prepared three-terminal Josephson junction based on the topological insulator Bi$_4$Te$_3$ and the superconductor Nb the transport properties are studied. The differential resistance maps as a function of two bias currents…

We combine electron beam lithography and masked anodization of epitaxial aluminium to define tunnel junctions via selective oxidation, alleviating the need for wet-etch processing or direct deposition of dielectric materials. Applying this…

Superconductivity · Physics 2021-11-10 A. Jouan , J. D. S. Witt , G. C. Gardner , C. Thomas , T. Lindemann , S. Gronin , M. J. Manfra , D. J. Reilly

We introduce a novel method for fabricating all-aluminum Josephson junctions with highly transmitted conduction channels. Such properties are typically associated with structures requiring intricate fabrication processes, such as atomic…

Mesoscale and Nanoscale Physics · Physics 2026-01-16 J. Griesmar , H. Riechert , M. Hantute , A. Peugeot , S. Annabi , Ç. Ö. Girit , G. O. Steffensen , A. L. Yeyati , E. Arrighi , L. Bretheau , J. -D. Pillet

$Al/AlO_x/Al$-layer systems are frequently used for Josephson junction-based superconducting devices. Although much work has been devoted to the optimization of the superconducting properties of these devices, systematic studies on…

Materials Science · Physics 2020-01-07 S. Fritz , L. Radtke , R. Schneider , M. Weides , D. Gerthsen