Related papers: Quantum and classical Shapiro steps in small Josep…
We present measurements of microwave-induced Shapiro steps in a superconducting nanobridge weak link in the dissipative branch of a hysteretic current-voltage characteristic. We demonstrate that Shapiro steps can be used to infer a reduced…
The properties of phase escape in a dc SQUID at 25 mK, which is well below quantum-to-classical crossover temperature $T_{cr}$, in the presence of strong resonant ac driving have been investigated. The SQUID contains two Nb/Al-AlO$_{x} $/Nb…
We revisit the interpretation of earlier low temperature experiments on Josephson junctions under the influence of applied microwaves. It was claimed that these experiments unambiguously established a quantum phenomenology with discrete…
Synchronization is a widespread phenomenon encountered in many natural and engineered systems with nonlinear classical dynamics. How synchronization concepts and mechanisms transfer to the quantum realm and whether features are universal or…
We consider microwave spectroscopy of Josephon junctions composed of hybridized Majorana states in topological 1-D superconductors. We point out how spectroscopic features of the junction appear in the current phase relation under microwave…
Quantum mechanics can strongly influence the noise properties of mesoscopic devices. To probe this effect we have measured the current fluctuations at high-frequency (5-90 GHz) using a superconductor-insulator-superconductor tunnel junction…
We analyze the emergence of Shapiro resonances in tunnel-coupled Bose-Einstein condensates, realizing a bosonic Josephson junction. Our analysis is based on an experimentally relevant implementation using magnetic double well potentials on…
We present a quantum electrical circuit with Josephson junctions formed of two anharmonic oscillators coupled with an interaction $g\gamma_{1}^{2}\gamma_{2}^{2}$ where $\gamma_{1}$ and $\gamma_{2}$ are position-like coordinates. This type…
We report a theoretical study of the macroscopic quantum tunneling (MQT) in small Josephson junctions containing randomly distributed two-level systems. We focus on the magnetic field dependent crossover temperature $T_{cr}$ between the…
The standard phenomenological Hamiltonian of a small superconducting Josephson junction in the charge regime (Cooper Pair Box) produces a model of the effective charge qubit with possible applications to quantum information processing. In…
Preliminary results are presented concerning static properties of a small Josephson junction under the influence of strong microwave radiation. We discuss the correspondence between a Brownian particle moving in a periodic potential and…
We report on quantum dot based Josephson junctions designed specifically for measuring the supercurrent. From high-accuracy fitting of the current-voltage characteristics we determine the full magnitude of the supercurrent (critical…
We developed a weak-linked Josephson junction time-domain simulation tool based on the Bardeen-Cooper-Schrieffer (BCS) theory to account for the electrodynamics of Cooper pairs and quasiparticles in the presence of thermal noise. The model,…
Various classical counterparts for the two-level pairing model in a many-fermion system are presented in the Schwinger boson representation. It is shown that one of the key ingredients giving the classical descriptions for quantal system is…
The difference between the phases of superconducting order parameter plays in superconducting circuits the role similar to that played by the electrostatic potential difference required to drive a current in conventional circuits. This…
Flux qubits, small superconducting loops interrupted by Josephson junctions, are successful realizations of quantum coherence for macroscopic variables. Superconductivity in these loops is carried by $\sim 10^6$ -- $10^{10}$ electrons,…
We provide a complete study of the phase diagram characterising the distinct dynamical regimes emerging in a three-dimensional Josephson junction in an ultracold quantum gas. Considering trapped ultracold superfluids separated into two…
The current-voltage I-V characteristics of a 1.2 \mum long Au nanowire contacted by superconducting electrodes were studied in details. Interestingly, the I-V curves over a wide range of temperatures display multiple steps at voltages V =…
The superconducting phase qubit combines Josephson junctions into superconducting loops and defines one of the promising solid state device implementations for quantum computing. While conventional designs are based on magnetically…
Detailed numerical simulations of intrinsic Josephson junctions of high temperature superconductors under external electromagnetic radiation are performed taking into account a charge imbalance effect. We demonstrate that the charge…