Related papers: Competition between Superconductivity and Weak Loc…
Metal mixed polymers are a cheap and effective way to produce flexible metals and superconductors. As part of an on-going effort to learn how to tune the properties of these systems with ion implantation, we present a study of the…
Ion-implantation of normally insulating polymers offers an alternative to depositing conjugated organics onto plastic films to make electronic circuits. We used a 50 keV nitrogen ion beam to mix a thin 10 nm Sn/Sb alloy film into the…
Magnetic field and electrostatically tuned superconductor-insulator (SI) transitions of ultrathin metal films with levels of disorder that place them near the disorder-tuned SI transition appear to be direct, continuous quantum phase…
The magnetoresistance of ultrathin insulating films of Bi has been studied with magnetic fields applied parallel and perpendicular to the plane of the sample. Deep in the strongly localized regime, the magnetoresistance is negative and…
We have used oxygen ions irradiation to generate controlled structural disorder in thin manganite films. Conductive atomic force microscopy CAFM), transport and magnetic measurements were performed to analyze the influence of the…
We investigate ultrathin superconducting TiN films, which are very close to the localization threshold. Perpendicular magnetic field drives the films from the superconducting to an insulating state, with very high resistance. Further…
Experimental and theoretical studies on transport in semiconductor samples with superconducting electrodes are reported. We focus on the samples close to metal-insulator transition. In metallic samples, a peak of negative magnetoresistance…
Artificial confinement of electrons by tailoring the layer thickness has turned out to be a powerful tool to harness control over competing phases in nano-layers of complex oxides. We investigate the effect of dimensionality on transport…
We study the interaction between a one dimensional magnetic nanostructure and a thin film superconductor. It is shown that different magnetic distributions produce characteristic magnetic field signatures. Moreover, the magnetic structure…
We present some of the recent theoretical studies on the impurity effects in conventional superconductors, such as magnetic and ordinary impurity effects in dirty and weak localization limits, and describe successfully unexplained…
We measured the magnetoresistance as a function of temperature down to 20mK and magnetic field for a set of underdoped PrCeCuO (x=0.12) thin films with controlled oxygen content. This allows us to access the edge of the superconducting dome…
Thin films of alkali metals when sandwiched at both surfaces by thin metal films loose their conductance. The superconducting proximity effect is used to investigate the change in the alkali film. On the length scale of the film thickness…
We study the effect of weak localization on the transition temperatures of superconductors using time-reversed scattered state pairs, and find that the weak localization effect weakens electron-phonon interactions. With solving the BCS…
We have investigated the gate-voltage dependence and the temperature dependence of the magnetoconductivity of amorphous indium-gallium-zinc-oxide thin-film transistors. A weak-localization feature is observed at small magnetic fields on top…
Disorder driven superconductor to insulator transition via intermediate metallic regime is reported in nano-crystalline thin films of molybdenum. The nano-structured thin films have been deposited at room temperature using DC magnetron…
The interplay between disorder and interactions can dramatically influence the physical properties of thin-film superconductors. In the most extreme case, strong disorder is able to suppress superconductivity as an insulating phase emerges.…
The magnetic field driven superconductor/insulator transition is studied in a large variety of $La_{2-x}Sr_xCuO_4$ thin films of various Sr dopings. Temperature dependence of the resistivity down to 4.2 or 1.5 K under high pulsed magnetic…
We address a recent experiment in which a strong decrease of the resistance of a superconducting film has been observed when a remote unbiased gate was placed above the film. Here we explain the experimental finding as a suppression of the…
We present results on disordered amorphous films which are expected to undergo a field-tuned Superconductor-Insulator Transition. Based on low-field data and I-V characteristics, we find evidence of a low temperature Metal-to-Superconductor…
The evolution with carrier concentration of the electrical properties of amorphous indium oxide (InO) thin films has been studied using electronic double layer transistor configurations. Carrier variations of up to 7 X 10^(14) carriers/cm^2…