4 research outputs found
Quantum suppression of superconductivity in ultrathin nanowires
We report measurements on ultrathin (<10 nm) nanowires produced by coating
carbon nanotubes with a superconducting amorphous MoGe alloy. We find that
nanowires can be superconducting or insulating depending on their normal state
resistance compared to -- the quantum resistance for
Cooper pairs. If the tunneling of quantum phase slips (QPS) is
prohibited due to strong damping, and so the wires stay superconducting. The
insulating state, observed if , is explained in terms of
proliferation of quantum phase slips and corresponding localization of Cooper
pairs. The observed superconductor-insulator transition is analogous to the
dissipative phase transition which takes place in Josephson Junctions at
(Penttila et al., Phys. Rev. Lett. Vol.82, p.1004, 1999)Comment: 14 pages, 3 figures. Accepted for publication in Natur