Related papers: JCO: Optimization Framework for Nonlinear Supercon…
The ability to non-dissipatively tune the Josephson coupling energy of Josephson junctions is a useful tool in frequency-tunable qubits. This is typically done by threading magnetic flux through two junctions connected in a loop, a geometry…
The fundamental noise limit of a phase-preserving amplifier at frequency $\omega /2\pi $ is the standard quantum limit $T_{q}=\hbar \omega /2k_{B}$. In the microwave range, the best candidates have been amplifiers based on superconducting…
Exploiting the intrinsic nonlinearity of superconducting Josephson junctions, we propose a scalable circuit with superconducting qubits (SCQs) which is very similar to the successful one now being used for trapped ions. The SCQs are coupled…
Planar Josephson junctions (JJs), based on common superconductors and III-V semiconductors, are sought for Majorana states and fault-tolerant quantum computing. However, with gate-tunable spin-orbit coupling (SOC), we show that the range of…
Tunable Josephson harmonics open new avenues for qubit design. We demonstrate a superconducting circuit element consisting of a tunnel junction in series with a SQUID loop, yielding a Josephson potential whose harmonic content is strongly…
A Josephson parametric amplifier (JPA) can create squeezed states of microwave light, lowering the noise associated with certain quantum measurements. We experimentally study how the JPA's pump influences the phase-sensitive amplification…
We propose a technique to couple the position operator of a nano mechanical resonator to a SQUID device by modulating its magnetic flux bias. By tuning the magnetic field properly, either linear or quadratic couplings can be realized, with…
We consider a superconducting loop with two weak links that encloses a magnetic flux. The weak links are unequal and are treated as Josephson junctions with non-sinusoidal phase dependence. We devise a model that takes into account the…
The most commonly used physical realization of superconducting qubits for quantum circuits is a transmon. There are a number of superconducting quantum circuits applications, where Josephson junction critical current reproducibility over a…
The simultaneous suppression of charge fluctuations and offsets is crucial for preserving quantum coherence in devices exploiting large quantum fluctuations of the superconducting phase. This requires an environment with both extremely low…
The continuous miniaturisation of metal-oxide-semiconductor field-effect transistors (MOSFETs) from long- to short-channel architectures has advanced beyond the predictions of Moore's Law. Continued advances in semiconductor electronics,…
Single-mode Josephson junction-based parametric amplifiers are often modeled as perfect amplifiers and squeezers. We show that, in practice, the gain, quantum efficiency, and output field squeezing of these devices are limited by usually…
We present a scalable, clockless up-down counter architecture implemented using single-flux quantum (SFQ) logic to enable efficient state management in superconductor digital systems. The proposed design eliminates the reliance on clocked…
Approaches to developing large-scale superconducting quantum processors must cope with the numerous microscopic degrees of freedom that are ubiquitous in solid-state devices. State-of-the-art superconducting qubits employ aluminum oxide…
Nonreciprocal microwave devices play several critical roles in high-fidelity, quantum-nondemolition (QND) measurement schemes. They separate input from output, impose unidirectional routing of readout signals, and protect the quantum…
Josephson junctions are essential devices in superconducting electronics and quantum computing hardware. Here we predict electrical control of the supercurrent in composite superconductor-insulator-ferroelectric-insulator-superconductor…
Superconductor Electronics (SCE) is a fast and power-efficient technology with great potential for overcoming conventional CMOS electronics' scaling limits. Nevertheless, the primary challenge confronting SCE today pertains to its…
We report the electrical transport in vertical Josephson tunnel junctions (area 400 $\mu m$$^2$) using GdBa$_2$Cu$_3$O$_7$$_{-\delta}$ electrodes and SrTiO$_3$ as an insulating barrier (with thicknesses between 1 nm and 4 nm). The results…
We develop a technique to overcome phase-mismatch in Josephson-junction traveling wave parametric amplifiers in order to achieve high gain over a broad bandwidth. Using "resonant phase matching," we design a compact superconducting device…
We introduce an efficient tensor network toolbox to compute the low-energy excitations of large-scale superconducting quantum circuits up to a desired accuracy. We benchmark this algorithm on the fluxonium qubit, a superconducting quantum…