Related papers: Scaling NbTiN-based ac-powered Josephson digital t…
We present a new process for fabricating vertical NbN-MgO-NbN Josephson junctions using self-aligned silicon nitride spacers. It allows for a wide range of junction areas from 0.02 um^2 to several 100 um^2. At the same time, it is suited…
High-fidelity, efficient quantum nondemolition readout of quantum bits is integral to the goal of quantum computation. As superconducting circuits approach the requirements of scalable, universal fault tolerance, qubit readout must also…
Reproducible high-Tc Josephson junctions have been made in a rather simple two-step process using ion irradiation. A microbridge (1 to 5 ?m wide) is firstly designed by ion irradiating a c-axis-oriented YBa2Cu3O7-? film through a gold mask…
Van der Waals (vdW) Josephson junctions can possibly accelerate the development of advanced superconducting device that utilizes the unique properties of two-dimensional (2D) transition metal dichalcogenide (TMD) superconductors such as…
We present investigations of Josephson charge-phase qubits inductively coupled to a radio-frequency driven tank-circuit enabling the readout of the states by measuring the Josephson inductance of the qubit. The circuits including junctions…
We used one-dimensional coupled sine-Gordon equations combined with heat diffusion equations to numerically investigate the thermal and electromagnetic properties of a $300\,\mu\mathrm{m}$ long intrinsic Josephson junction stack consisting…
The integration of semiconductor Josephson junctions (JJs) in superconducting quantum circuits provides a versatile platform for hybrid qubits and offers a powerful way to probe exotic quasiparticle excitations. Recent proposals for using…
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…
Currently, superconductor digital integrated circuits fabricated at HYPRES, Inc. can operate at clock frequencies of ~ 40 GHz. The circuits present multilayered structures containing tens of thousands of Nb/Al/AlOx/Nb Josephson junctions…
Providing radio frequency (RF) signals to circuits working in cryogenic conditions requires bulky and expensive transmission cabling interfacing specialized RF electronics anchored at room temperature. Superconducting Josephson junction…
The physics of the "Pi" phase shift in ferromagnetic Josephson junctions enables a range of applications for spin-electronic devices and quantum computing. In this respect our research is devoted to the evaluation of the best materials for…
We demonstrate enhanced relaxation and dephasing times of transmon qubits, up to ~ 60 \mu s by fabricating the interdigitated shunting capacitors using titanium nitride (TiN). Compared to lift-off aluminum deposited simultaneously with 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…
Existing concepts of reversible superconducting circuits as well as demonstrated adiabatic circuits require three-phase bias/clock signals generated by room temperature sources. A while ago, we suggested that a multi-phase bias/clock could…
Since the discovery of the unconventional copper-oxide high-transition-temperature superconductors (HTS), researchers have explored many methods to fabricate superconducting tunnel junctions from these materials for both superconducting…
Controlled fabrication of twisted van der Waals heterostructures is essential to unlock the full potential of moire materials. However, achieving reproducibility remains a major challenge, particularly for air-sensitive materials such as…
We systematically study the performance of compact lumped element planar microwave $\mathrm{Nb_{70}Ti_{30}N}$ (NbTiN) resonators operating at 5 GHz in external in-plane magnetic fields up to 440 mT, a broad temperature regime from 2.2 K up…
Van der Waals (vW) Josephson junctions (JJs) realized by stacking materials such as few-layered NbSe2, offers a new landscape to realize superconducting quantum devices with superior properties owing to its crystalline nature and…
The narrow bandgap of semiconductors allows for thick, uniform Josephson junction barriers, potentially enabling reproducible, stable, and compact superconducting qubits. We study vertically stacked van der Waals Josephson junctions with…
Nanoscale superconductor-semiconductor hybrid devices are assembled from InAs semiconductor nanowires individually contacted by aluminum-based superconductor electrodes. Below 1 K, the high transparency of the contacts gives rise to…