Related papers: Topological quantization and degeneracy in Josephs…
We report the results of ac sheet conductance measurements performed on fully frustrated square arrays of Josephson junctions whose coupling energy is periodically modulated in one of the principal lattice directions. Such systems are…
Topological materials and their unusual transport properties are now at the focus of modern experimental and theoretical research. Their topological properties arise from the bandstructure determined by the atomic composition of a material…
Employing mutual-inductance measurements we study the magnetic field dependence of complex AC susceptibility of artificially prepared highly ordered (periodic) two-dimensional Josephson junction arrays of unshunted Nb-AlO_x-Nb junctions.…
We have measured the depinning of trapped kinks in a ratchet potential using a fabricated circular array of Josephson junctions. Our ratchet system consists of a parallel array of junctions with alternating cell inductances and junctions…
We present experimental investigations of transport properties in the insulating phase of two-dimensional Josephson-junction arrays (JJAs) by systematically changing the ratio of Josephson energy $E_\mathrm{J}$ and charging energy…
We observe a series of discontinuities in the above gap current/voltage characteristics of highly transmissive Nb/Si superconductor/semiconductor interfaces. The bias at which each switch occurs decreases in quantized steps as a function of…
One of the key problems facing superconducting qubits and other Josephson junction devices is the decohering effects of bi-stable material defects. Although a variety of phenomenological models exist, the true microscopic origin of these…
We have investigated the dynamics of vortices in a dilute two dimensional Josephson junction array where a fraction of the superconducting islands is missing. We have used the multiple trapping model to calculate the mobility of vortices…
We compute the current voltage characteristic of a chain of identical Josephson circuits characterized by a large ratio of Josephson to charging energy that are envisioned as the implementation of topologically protected qubits. We show…
A critical value in the product of the anisotropy parameter and the magnetic field is observed in interlayer Josephson-vortex systems by extensive Monte Carlo simulations. Below/above this critical value the thermodynamic phase transition…
A model of a ladder of Josephson junctions in a magnetic field is considered. The topological features of the zero-temperature phase diagram, as a function of charging energy and small deviations from commensurability of the vortex lattice,…
By employing mutual-inductance technique and using a high-sensitive bridge, we have thoroughly investigated (both experimentally and theoretically) the temperature and magnetic field dependence of complex AC susceptibility of artificially…
Quantum systems are often described by parameter-dependent Hamiltonians. Points in parameter space where two levels are degenerate can carry a topological charge. Here we theoretically study an interacting two-spin system where the…
We study persistent currents in a Josephson junction array wrapped around a cylinder. The $T=0$ quantum statistical mechanics of the array is equivalent to the statistical mechanics of a classical $xy$ spin system in 2+1 dimensions at the…
By means of electrical transport measurements we have studied the rectified motion of vortices in ratchet potentials engineered on over-damped Josephson junction arrays. The rectified voltage as a function of the vortex density shows a…
We experimentally studied the effect of positional disorder on a Josephson junction array with $f = n$, ${1/2} + n$, or ${2/5} + n$ flux quanta per unit cell for integral $n$. This system provides an experimental realization of a…
We consider the conductivity of excitations in short chains of optical cavities with two-level atoms in the models of JCH type, where either we explicitly take into account the photon jumps between atoms, or is merely a transfer of…
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 analyze the electrical characteristics of a circuit consisting of a free thin-film magnetic layer and source and drain electrodes that have opposite magnetization orientations along the free magnet's two hard directions. We find that…
Josephson junctions with an intrinsic phase shift of pi, so-called pi Josephson junctions, can be realized by a weak link of a d-wave superconductor with an appropriate boundary geometry. A model for the pairing potential of an according…