Quantum size effect in single-crystalline bismuth nanorods

Phase Slip Phenomena in Ultra-Thin Superconducting Wires

We present results on phase-slip phenomena in a superconducting wire which can be considered as quasi-one dimensional (1D) if its characteristic transverse dimension \( \sqrt \sigma\) (√ being the cross section) is smaller than the coherence length Λ(T). The shape of the bottom part of the resistive transition R(T) of a 1D superconducting strip is described by the model of phase slips activation. If the wire is infinitely long, then there is always a finite probability that a small part of the sample is instantly driven normal.

Quantum fluctuations in ultranarrow superconducting aluminum nanowires

Progressive reduction of the effective diameter of a nanowire is applied to trace evolution of the shape of the superconducting transition $R(T)$ in quasi-one-dimensional aluminum structures. In nanowires with effective diameter $\ensuremath{\leqslant}15\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ the $R(T)$ dependences are much wider than predicted by the model of thermally activated phase slips. The effect can be explained by quantum fluctuations of the order parameter. Negative magnetoresistance is observed in the thinnest samples. Experimental results are in reasonable agreement with existing theoretical models. The effect should have a universal validity, indicating a breakdown of the zero-…

Size Dependent Breakdown of Superconductivity in Ultranarrow Nanowires

Below a certain temperature Tc (typically cryogenic), some materials lose their electric resistance R entering a superconducting state. Folowing the general trend toward a large scale integration of a greater number of electronic components, it is desirable to use superconducting elements in order to minimize heat dissipation. It is expected that the basic property of a superconductor, i.e. dissipationless electric current, will be preserved at reduced scales required by modern nanoelectronics. Unfortunately, there are indications that for a certain critical size limit of the order of 10 nm, below which a "superconducting" wire is no longer a superconductor in a sense that it acquires a fin…