Superconductor-insulator transition in quasi-one-dimensional nanowires

We have studied a large group of superconducting MoGe nanowires fabricated by a molecular templating technique. A well-defined superconductor-insulator transition (SIT) is observed in homogeneous wires with lengths less than ~200 nm. The total normal state resistance of the wire is found to be the control parameter for this transition with the critical point occurring near the quantum of resistance for Cooper pairs. Wires in the superconducting phase of the SIT are well described by the Langer-Ambegaokar-McCumber-Halperin theory of thermally activated phase slips. No resistance “tails” characteristic of quantum phase slips were observed. Wires in the insulating phase of the SIT follow the predictions of the theory of weak Coulomb blockade in a diffusive normal metal. Longer wires display signs of a “mixed” behavior that is similar to that found for inhomogeneous wires in which a single wire acts as a combination of two or more superconducting and/or insulating sections.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2012

Author dc:creator

• Bollinger, Anthony Travis

Contributors dc:contributor

• Bezryadin, Alexey

• Molybdenum Germanium (MoGe)
• superconducting nanowires
• superconductor insulator transition
• superconductivity
• Langer, Ambegaokar, McCumber and Halperin (LAMH) theory

Statement dc:rights

• © 2005 Anthony Travis Bollinger

Language dc:language

en

Identifier

5187923

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/32092