The sensitivity of planar waveguide sensor containing dielectric, superconductor, and left-handed materials has been theoretically investigated. The proposed waveguide sensor in this study consists of a metamaterial film bounded by a dielectric cover and a superconductor substrate. The variation of the sensor sensitivity are found to be strongly depended on the metamaterial film, the film thick...

beta-YbAlB4 is the first Yb-based heavy fermion superconductor with Tc = 80 mK. Our study using high-purity single crystals reveals that strongly type-II heavy fermion superconductivity emerges from the non-Fermi-liquid state with enhanced ferromagnetic fluctuations. High sensitivity of Tc to sample purity indicates strong pair-breaking effects due to impurities, probably of nonmagnetic type, s...

A feasible strategy to realize the Majorana fermions is searching for a simple compound with both bulk superconductivity and Dirac surface states. In this paper, we performed calculations of electronic band structure, Fermi states, as well measured resistivity, magnetization, specific heat TlSb CsCl-type structure. The structure show that semimetal when spin-orbit coupling taken into account. M...

A theory of the proximity effect in normal metal–multiband superconductor hybrid structures is formulated within the quasiclassical Green’s function formalism. The quasiclassical boundary conditions for multiband hybrid structures are derived in the dirty limit. It is shown that the existence of multiple superconducting bands manifests itself as the occurrence of additional peaks in the density...

Reflectionless-tunneling was observed in Nb/GaAs superconductor/semiconductor junctions fabricated through a two-step procedure. First, periodic δ-doped layers were grown by molecular beam epitaxy near the GaAs surface, followed by an As cap layer to protect the surface during ex-situ transfer. Second, Nb was deposited by dc-magnetron sputtering onto the GaAs(001) 2× 4 surface in-situ after the...

I construct a minimal formalism to describe transport of non separable correlations arising when a superconductor is in contact with several electrodes (being ferromagnetic or normal metal). Transport theory is expressed in terms of effective single site Green’s functions. Part of the circuit is decimated exactly by renormalizing only one physical parameter (the density of states). I show that ...

Scanning tunneling microscopy (STM) studies of the high-T superconductors have led to a number of important discoveries. In particular, STM has revealed spatial patterns in electronic density due to phenomena such as checkerboard order and quasiparticle interference. This thesis presents two studies of these patterns and their implications. In the first, I present a doping and temperature depen...

We study in detail, solving the Bogoliubov-de Gennes equations, the magnetic field, supercurrent and order parameter profiles originated by a solenoid or magnetic whisker inserted in a type-II superconductor. We consider solutions of different vorticities, n, in the various cases. The results confirm the connection between the vorticity, the internal currents and the boundstates in a self-consi...

Superconductivity of n-doped SrTiO3, which remained enigmatic for half a century, is treated as a particular case of nonadiabatic phonon pairing. Motivated by experiment, we suggest the existence of the mobility edge at some dopant concentration. The itinerant part of the spectrum consists of three conduction bands filling by electrons successively. Each subband contributes to the superconducti...

Progress toward a Josephson voltage standard for fast dc measurements and accurate ac waveform synthesis is described. A superconductor-normal-superconductor (SNS) junction process is used to make 5 mA critical current arrays with up to 32 768 junctions. With rf excitation at 11 GHz these arrays generate milliampere constant-voltage steps. A bias control circuit that provides output current amp...