Related papers: Macroscopic Quantum Tunneling and Quasiparticle Di…
As low-loss non-linear elements, Josephson junctions are the building blocks of superconducting qubits. The interaction of the qubit degree of freedom with the quasiparticles tunneling through the junction represent an intrinsic relaxation…
Switching current distributions have for decades been an indispensable diagnostic tool for studying Josephson junctions. They have played a key role in testing the conjecture of a macroscopic quantum state in junctions at millikelvin…
We consider a symmetric 0-pi Josephson junction of length $L$, which classically can be in one of two degenerate ground states up or down, corresponding to supercurrents circulating clockwise or counterclockwise around the 0-pi boundary.…
Josephson junctions form the essential non-linearity for almost all superconducting qubits. The junction is formed when two superconducting electrodes come within $\sim$1 nm of each other. Although the capacitance of these electrodes is a…
It is important to know the decoherence mechanism of a qubit based on Josephson junctions. At low temperatures, as quasiparticle concentration becomes exponentially small, one needs to consider energy transfer from tunneling electrons to…
A single spin in a Josephson junction can reverse the flow of the supercurrent. At mesoscopic length scales, such $\pi$-junctions are employed in various instances from finding the pairing symmetry to quantum computing. In Yu-Shiba-Rusinov…
A resonantly driven bosonic Josephson junction supports stable collective excitations, or quasiparticles, which constitute analogs of the Trojan wave packets previously explored with Rydberg atoms in strong microwave fields. We predict a…
Tunnelling between non-centrosymmetric superconductors with significant spin-orbit splitting is studied theoretically in a two-band treatment of the problem. We find that the critical Josephson current may be modulated by changing the…
The experimental observation of quantum phenomena in mechanical degrees of freedom is difficult, as the systems become linear towards low energies and the quantum limit, and thus reside in the correspondence limit. Here we investigate how…
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…
A quantum dot weakly coupled to two normal metal leads exhibits resonant transmission when one of the dot energy levels lies within the applied bias window. But when the quantum dot is sidecoupled to the transport channel, transmission in…
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…
We have developed a scheme for a high resolution measurement of the switching current distribution of a current biased Josephson tunnel junction using a timing technique. The measurement setup is implemented such that the digital control…
We report on the first realization of a single bosonic Josephson junction, implemented by two weakly linked Bose-Einstein condensates in a double-well potential. In order to fully investigate the nonlinear tunneling dynamics we measure the…
Theoretically, Josephson junction (JJ) arrays can exhibit either a superconducting or insulating state, separated by a quantum phase transition (QPT). In this work, we analyzed published data on QPTs in three one-dimensional arrays and two…
We derive a mesoscopic theory of the Josephson junction from non-relativistic scalar electrodynamics. Our theory reproduces the Josephson relations with the canonical current phase relation acquiring a weak second harmonic term, and it…
We investigate the dynamics of the phase variable of an ideal underdamped Josephson junction in switching current experiments. These experiments have provided the first evidence for macroscopic quantum tunneling in large Josephson junctions…
We show that a system of Josephson junctions coupled via low-resistance tunneling contacts to graphene substrate(s) may effectively operate as a current switching device. The effect is based on the dissipation-driven…
We discuss the possible influence of a cosmic magnetic field on the macroscopic quantum tunneling process associated, in a cosmological context, to the decay of the "false vacuum." We find a close analogy with the effects of an external…
Quantum fluctuations of the phases of the order parameter in 2D arrays of mesoscopic Josephson junctions and their effect on the destruction of superconductivity in the system are investigated by means of a quantum-cosine model that is free…