Related papers: Self-shunted Al/AlOx/Al Josephson junctions
We present low-temperature measurements of the low-frequency $1/f$ noise arising from an ensemble of two-level fluctuators in the oxide barrier of Al/AlO$_{x}$/Al Josephson junctions. The fractional noise power spectrum of the…
Josephson superconducting qubits and parametric amplifiers are prominent examples of superconducting quantum circuits that have shown rapid progress in recent years. With the growing complexity of such devices, the requirements for…
The microscopic structure of ultra-thin oxide barriers often plays a major role in modern nano-electronic devices. In the case of superconducting electronic circuits, their operation depends on the electrical non-linearity provided by one…
The effect of thermal fluctuations in Josephson junctions is usually analysed using the Ambegaokar-Halperin (AH) theory in the context of thermal activation. "Enhanced" fluctuations, demonstrated by broadening of current-voltage…
We present the measurement of superconductor / ferromagnetic Josephson junctions, based on an epitaxial Nb bottom electrode and epitaxial Fe20Ni80 barrier. Uniform junctions have been fabricated with a barrier thicknesses in the range 2-12…
Reproducible High Tc Josephson junctions have been made in a rather simple two-step process using ion irradiation. A microbridge 1 to 5 micrometers wide is firstly designed by ion irradiating a c-axis-oriented YBa2Cu3O7 film through a gold…
Tunneling defects in disordered materials form spurious two-level systems which are a major source of decoherence for micro-fabricated quantum devices. For superconducting qubits, defects in tunnel barriers of submicrometer-sized Josephson…
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…
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.…
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…
We study, both theoretically and experimentally, the features on the current-voltage characteristic of a highly transparent Josephson junction caused by transition of the superconducting leads to the normal state. These features appear due…
In this work, we briefly overview various options for Josephson junctions which should be scalable down to nanometer range for utilization in nanoscale digital superconducting technology. Such junctions should possess high values of…
High quality epitaxial NbN/MgO/NbN Josephson junctions have been realized with MgO barriers up to a thickness of d=1 nm. The junction properties coherently scale with the size of barrier, and low critical current densities down to 3…
We report microwave spectroscopy of Josephson junctions chains made from an epitaxial Al/InAs heterostructure. The chains exhibit superinductance, with characteristic wave impedance exceeding $R_{Q} = \hbar/(2e)^{2}$. The planar nature of…
The quality of a superconductor-normal metal-superconductor Josephson junction (JJ) depends crucially on the transparency of the superconductor-normal metal (S/N) interface. We demonstrate a technique for fabricating planar JJs with perfect…
We implemented, optimized and fully tested over multiple runs a superconducting Josephson junction fabrication process tailored for the integrated digital circuits that are used for control and readout of superconducting qubits operating at…
We report an experimental study of induced superconductivity in Ge hut nanowire Josephson junctions. The Ge hut nanowires are grown on prepatterned SiGe ridges via molecular beam epitaxy (MBE) and Josephson junction devices are fabricated…
Superconducting qubits have motivated the exploration of Josephson-junction technologies beyond quantum computing, with emerging applications in low-energy photon and phonon detection for astrophysics and dark matter searches. Achieving…
An application-specific Josephson generator is being developed as an on-chip calibration source for single-microwave-photon detectors operating below $T \sim $100 mK in the frequency range from 110 to 170 GHz. The targeted calibration power…
Conventional Josephson metal-insulator-metal devices are inherently underdamped and exhibit hysteretic current-voltage response due to a very high subgap resistance compared to that in the normal state. At the same time, overdamped…