Related papers: Threshold Resistance in the DC Josephson Effect
We introduce a new approach to the Josephson effect in SIS tunnel junctions. The Josephson coupling energy is calculated from the overlap of real space Cooper pair wavefunctions in two superconductors through an insulating barrier. It is…
We observe a subharmonic gap sturucture (SGS) and the Josephson effect in superconducting scanning tunneling microscope junctions with resistances below 100 kOhm. The magnitude of the n=2 SGS is shown to scale with the square of the…
Superconductor-insulator-superconductor tunnel junctions have been fabricated on MgB2 that display Josephson and quasiparticle currents. These junctions exhibit a gap magnitude, Delta~2.5 meV, that is considerably smaller than the BCS…
In the tunnel limit, the current-phase relation of Josephson junctions can be expanded as $I(\phi)=I_1\sin\phi+I_2\sin 2\phi$. Standard BCS theory predicts that $I_1R_N\sim\Delta/e$ and $I_2/I_1\sim D$, where $R_N$ is the resistance of the…
In the classical Josephson effect the phase difference across the junction is well defined, and the supercurrent is reduced only weakly by phase diffusion. For mesoscopic junctions with small capacitance the phase undergoes large quantum…
We study large arrays of mesoscopic junctions between gapless superconductors where the tunneling processes of both, particle-hole and Cooper, pairs give rise to a strongly retarded effective action which, contrary to the standard case, can…
When a tunneling barrier between two superconductors is formed by a normal material that would be a superconductor in the absence of phase fluctuations, the resulting Josephson effect can undergo an enormous enhancement. We establish this…
Tunneling data on magnesium diboride, MgB_2, are reviewed with a particular focus on superconductor-insulator-superconductor (SIS) junctions formed by a break-junction method. The collective tunneling literature reveals two distinct energy…
The Josephson effect describes the generic appearance of a supercurrent in a weak link between two superconductors. Its exact physical nature however deeply influences the properties of the supercurrent. Detailed studies of Josephson…
We investigate the Josephson effect in S$_{\rm F}$XS$_{\rm F}$ junctions, where S$_{\rm F}$ is a superconducting material with a ferromagnetic exchange field, and X a weak link. The critical current $I_c$ increases with the (antiparallel)…
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 study the Josephson effect for a topologically nontrivial superconducting (TS) wire with Majorana fermion end states and tunnel-coupled to s-wave BCS superconducting (S) electrodes. In an S-TS junction, no supercurrent flow is possible…
An extension of the Ambegaokar-Baratoff relation to a superconductor-insulator-superconductor (SIS) Josephson junction with multiple tunneling channels is derived. Appling the resultant relation to a SIS Josephson junction formed by an…
For Josephson junctions based on s-wave superconductors, time-reversal symmetry is known to allow for powerful relations between the normal-state junction properties, the excitation spectrum, and the Josephson current. Here we provide…
We develop a microscopic analysis of superconducting and dissipative currents in junctions between superconductors with d-wave symmetry of the order parameter. We study the proximity effect in such superconductors and show that for certain…
We report on transport properties of Josephson junctions in hybrid superconducting-topological insulator devices, which show two striking departures from the common Josephson junction behavior: a characteristic energy that scales inversely…
Three-dimensional topological insulators (TI's) in proximity with superconductors are expected to exhibit exotic phenomena such as topological superconductivity (TSC) and Majorana bound states (MBS), which may have applications in…
We investigate the current-voltage characteristics of high-transparency superconductor-insulator-normal metal (SIN) junctions with the specific tunnel resistance below 30 kOhm per square micron. The junctions were fabricated from different…
We report the demonstration of dc and ac Josephson effects as well as tunneling spectroscopy measurements on Nb/Al2O3/Al/MgB2 thin films heterostructures. Data on dc Josephson effect suggest the presence of two characteristic critical…
Mesoscopic superconducting-normal-metal-superconducting (S-N-S) junctions with a large separation between the superconducting electrodes (i.e. wide junctions) exhibit nonequilibrium supercurrents, even at temperatures for which the…