Quantum breakdown of superconductivity in low-dimensional materials

In order to understand the emergence of superconductivity it is useful to study and identify the various pathways leading to the destruction of superconductivity. One way is to use the increase in Coulomb-repulsion due to the increase in disorder, which overpowers the attractive interaction responsible for Cooper-pair formation. A second pathway, applicable to uniformly disordered materials, is the competition between superconductivity and Anderson localization, which leads to electronic granularity in which phase and amplitude fluctuations of the superconducting order parameter play a role. Finally, a third pathway is an array of superconducting islands coupled by some form of proximity-effect, due to Andreev-reflections, and which leads from a superconducting state to a state with finite resistivity, which appears like a metallic groundstate. This review summarizes recent progress in understanding of these different pathways, including experiments in low dimensional materials and application in superconducting quantum devices.Comment: Review Articl

Scaling behavior and parasitic series resistance in disordered organic field-effect transistors

\u3cp\u3eThe scaling behavior and transfer characteristics of solution-processed disordered organic thin-film transistors were discussed. Field-effect mobility and parasitic series resistance were studied. Results showed that parasitic resistance depends on applied gate voltage and decreases with increasing field-effect mobility.\u3c/p\u3

1991 Census Cheshire; Cheshire atlas

SIGLEAvailable from British Library Document Supply Centre- DSC:OP-LG/8020 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Direct evidence for Cooper pairing without a spectral gap in a disordered superconductor above T c

The idea that preformed Cooper pairs could exist in a superconductor at temperatures higher than its zero-resistance critical temperature (Tc) has been explored for unconventional, interfacial, and disordered superconductors, but direct experimental evidence is lacking. We used scanning tunneling noise spectroscopy to show that preformed Cooper pairs exist up to temperatures much higher than Tc in the disordered superconductor titanium nitride by observing an enhancement in the shot noise that is equivalent to a change of the effective charge from one to two electron charges. We further show that the spectroscopic gap fills up rather than closes with increasing temperature. Our results demonstrate the existence of a state above Tc that, much like an ordinary metal, has no (pseudo)gap but carries charge through paired electrons