Superconductivity in one dimension

TL;DR

This paper reviews recent advances in understanding superconductivity in one-dimensional nanostructures, highlighting the effects of quantum phase slips and the transition from superconducting to normal states at nanoscale diameters.

Contribution

It provides a comprehensive overview of recent theoretical and experimental progress in the field of superconductivity in quasi-one-dimensional nanostructures.

Findings

Quantum phase slips cause resistance in nanowires below 50 nm.

Proliferation of quantum phase slips leads to a superconducting-normal crossover at ~10 nm.

Superconducting nanorings exhibit phenomena related to quantum phase slips and parity effects.

Abstract

Superconducting properties of metallic nanowires can be entirely different from those of bulk superconductors because of the dominating role played by thermal and quantum fluctuations of the order parameter. For superconducting wires with diameters below $ \sim 50$ nm quantum phase slippage is an important process which can yield a non-vanishing wire resistance down to very low temperatures. Further decrease of the wire diameter, for typical material parameters down to $\sim 10$ nm, results in proliferation of quantum phase slips causing a sharp crossover from superconducting to normal behavior even at T=0. A number of interesting phenomena associated both with quantum phase slips and with the parity effect occur in superconducting nanorings. We review recent theoretical and experimental activities in the field and demonstrate dramatic progress in understanding of the phenomenon of superconductivity in quasi-one-dimensional nanostructures.