Related papers: Self-shunted Al/AlOx/Al Josephson junctions
We present a novel shadow evaporation technique for the realization of junctions and capacitors. The design by E-beam lithography of strongly asymmetric undercuts on a bilayer resist enables in-situ fabrication of junctions and capacitors…
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…
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…
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…
Josephson junctions (JJs) are the key element of many devices operating at cryogenic temperatures. Development of time-efficient wafer-scale JJ characterization for process optimization and control of JJ fabrication is essential. Such…
We have studied low-frequency resistance fluctuations in shadow-evaporated Al/AlOx/Al tunnel junctions. Between 300 K and 5 K the spectral density follows a 1/f-law. Below 5 K, individual defects distort the 1/f-shape of the spectrum. The…
We introduce a simplified fabrication technique for Josephson junctions and demonstrate superconducting Xmon qubits with $T_1$ relaxation times averaging above 50$~\mu$s ($Q>$1.5$\times$ 10$^6$). Current shadow-evaporation techniques for…
One of the practical limitations of solid-state superconducting quantum processors technology is frequency crowding due to low qubits fabrication reproducibility. Josephson junction 100 nm-scale nonlinear inductance of the qubits still…
$Al/AlO_x/Al$-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…
Bi$_2$Se$_3$ nanoribbons, grown by catalyst-free Physical Vapour Deposition, have been used to fabricate high quality Josephson junctions with Al superconducting electrodes. The conductance spectra (dI/dV) of the junctions show clear…
The effect of dc electrical stress and breakdown on Josephson and quasiparticle tunneling in Nb/Al/AlOx/Nb junctions with ultrathin AlOx barriers typical for applications in superconductor digital electronics has been investigated. The…
We have developed a technique to fabricate sub-micron, 0.6 um x 0.6 um Al-AlOx-Nb tunnel junctions using a standard e-beam resist, angle evaporation and double oxidation of the tunneling barrier, resulting in high quality niobium, as…
Metal-Insulator-Metal tunnel junctions (MIMTJ) are common throughout the microelectronics industry. The industry standard AlOx tunnel barrier, formed through oxygen diffusion into an Al wetting layer, is plagued by internal defects and…
We show that less than 10% of the barrier area dominates the electron tunneling in state-of-art Al/AlOx/Al Josephson junctions. They have been studied by transmission electron microscopy, specifically using atomic resolution annular dark…
Josephson junctions with iron pnictides open the way for fundamental experiments on superconductivity in these materials and their application in superconducting devices. Here, we present hybrid Josephson junctions with a…
We investigate tunnel ferromagnetic Josephson junctions based on Superconductor-Insulator-thin superconductor-Ferromagnet-Superconductor multilayers. A comparative study of their electrodynamic properties is performed for junctions with…
The zero-voltage state of a Josephson junction biased with constant current consists of a set of metastable quantum energy levels. We probe the spacings of these levels by using microwave spectroscopy to enhance the escape rate to the…
We tested oxidized titanium layers as barriers for hybrid Josephson junctions with high $I_cR_n$-products and for the preparation of junctions for tunneling spectroscopy. For that we firstly prepared junctions with conventional…
To increase integration scale of superconductor electronics, we are developing a new, SFQ7ee, node of the fabrication process at MIT Lincoln Laboratory. In comparison to the existing SFQ5ee node, we increased the number of fully planarized…
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,…