Related papers: Critical current in Nb-Cu-Nb junctions with non-id…
The high tunability of the density of states of graphene makes it an ideal probe of quantum transport in different regimes. In particular, the supercurrent that can flow through a non-superconducting (N) material connected to two…
A method to measure the electrical connectivity between square superconducting plates joined by weak link interfaces is presented. It is based on observation of lines where the flow of critical current abruptly changes direction due to the…
We study the critical current of a S/F-I-N/S tunnel structure - a proximity coupled superconductor (S) with thin ferromagnetic (F) and nonmagnetic (N) metals separated by an insulating (I) barrier - in an external magnetic field. The…
We present a perspective on a new critical-current-by-design paradigm to tailor and enhance the current-carrying capacity of applied superconductors. Critical current by design is based on large-scale simulations of vortex matter pinning in…
In recent years there has been a number of proposals of thermal devices operating in the near-field regime that make use of phase-transition materials. Here, we present a theoretical study of near-field thermal diodes and transistors that…
Studies of the superconducting proximity effect in normal conductor/superconductor $(N/S)$ junctions almost universally assume no effective electron-electron coupling in the $N$ region. While such an approximation leads to a simple…
Two principles govern the critical temperature for superconducting transitions: (1)~intrinsic strength of the pair coupling and (2)~effect of the many-body environment on the efficiency of that coupling. Most discussions take into account…
Superconducting tunnel junctions are being developed for application as photon detectors in astronomy. We present the latest results on the development of very high quality, very low critical temperature junctions, fabricated out of pure Al…
We present a theoretical study of the density of states and supercurrent in diffusive superconductor-normal metal-superconductor (SNS) junctions. In particular, we study the influence on these two equilibrium properties of both an arbitrary…
We study the behavior of the critical current, Ic(H,T), of pure and Fe doped NbSe2 crystals in the denominated disordered vortex region, limited by the critical field Hc2(T) and the field Hp(T) at which the peak effect in Ic(H,T) is…
Numerical modeling of dependences ``critical current -- external magnetic field'' for geometrically symmetric $0-\pi$ Josephson junctions is performed. The calculation of critical current is reduced to non-linear eigenvalue problem. The…
Currently, superconductor digital integrated circuits fabricated at HYPRES, Inc. can operate at clock frequencies of ~ 40 GHz. The circuits present multilayered structures containing tens of thousands of Nb/Al/AlOx/Nb Josephson junctions…
The theory of ferromagnetic Pi-junction near the critical temperature is presented. It is demonstrated that in the dirty limit the modified Usadel equation adequately describes the proximity effect in ferromagnets. To provide the…
We have measured a long-range supercurrent in Josephson junctions containing Co (a strong ferromagnetic material) when we insert thin layers of either PdNi or CuNi weakly-ferromagnetic alloys between the Co and the two superconducting Nb…
The doping dependence of the critical current density, $J_{c}$, was measured in a series of high quality c-axis oriented ${\rm Bi_2Sr_2CaCu_2O_{8+\delta}}$ thin films. For each doping level we measured the temperature dependence of $J_{c}$.…
We consider the critical temperature for superconductivity, defined via the linear BCS equation. We prove that at weak coupling the critical temperature for a sample confined to a quadrant in two dimensions is strictly larger than the one…
We have developed a technique to fabricate sub-micron, 0.6 um x 0.6 um Al-AlOx-Nb tunnel junctions using a standard e-beam resist, angle evaporation and double oxidation of the tunneling barrier, resulting in high quality niobium, as…
We analyze the dc Josephson effect in a ballistic superconductor/half-metal/superconductor junction by means of the Bogoliubov de Gennes equations. We study the role of spin-active interfaces and compare how different superconductor…
The ability to simulate realistically the electronic structure of superconducting materials is important to understand and predict various properties emerging in both the superconducting topological and spintronics realms. We introduce a…
Superconducting single quantum logic integrated circuits traditionally exploit magnetron sputtered niobium thin films on silicon oxide substrates. The sputtering depends on multiple process parameters, which dramatically affect mechanical,…