Experimental limits of the observation of thermally activated phase-slip mechanism in superconducting nanowires

Abstract

The shape of experimentally observed R͑T͒ transition of thin superconducting wires is analyzed. From theoretical point of view, broadening of the transition in quasi-one-dimensional superconducting channels is typically associated with phase-slip mechanism. It is shown that such interpretation can be misleading if to consider geometrical inhomogeneity and finite dimensions of real samples studied in experiments. The analysis is based on experimental fact that for many superconducting materials the critical temperature depends on the characteristic dimension of a sample: film thickness or wire cross section.

Healing Effect of Controlled Anti‐Electromigration on Conventional and High‐Tc Superconducting Nanowires

“…As w decreases, so does ∆F and consequently the rate of phase slips and the associated dissipation increase. It is also worth noting that the narrowing of the constriction does not seem to produce a change in the critical temperature as could be expected from previous reports 35 . This effect results from the fact that the voltage contacts are 500 nm apart from the constriction and therefore capture also the superconducting transition of the leads which remains unchanged after EM.…”

Ion beam shaping and downsizing of nanostructures

“…The described technique can be utilized for a wide variety of materials whenever there is a need to reduce the size or/and reshape nanostructures in controllable and homogenous way. The method was primarily developed for academic research where the development of quantum size phenomenon has been studied down to sub-10 nm dimensions [5][6][7][8][9]. The approach eliminates uncertainty typical for samples fabricated in separate runs: if there were no structural imperfections in the original sample, they cannot be introduced later by the low energy ion bombardment.…”

“…In this configuration all points of a structure are sputtered homogeneously with an average rate shown in figure 3 with dashed horizontal line. This approach was used in our earlier studies of quantum size phenomena, where we were able to trace the evolution of electron transport properties on the same sample while progressive and uniform reduction of its characteristic dimension(s) [5][6][7][8][9]. figure 4(a)), while in the opposite limit the trapezoid becomes 'sharper' finally degenerating into a triangle ( figure 4(b)).…”

“…Various types of systems have been successfully processed: insulators (sapphire, Si/SiO x , mica), semicondctors (Si), metals (Al, Cu, Bi, Ti) [5][6][7][8][9] and hybrid metal-oxide-metal nanostructures (e.g. single electron transistors) [5].…”

Quantum fluctuations in ultranarrow superconducting aluminum nanowires

“…In spite of the intensive research in the field, the matter is far from being settled. From an experimental point of view, to some extent, the inhomogeneity of a nanowire might lead to a broad superconducting transition R(T ) which can be erroneously associated with the QPS mechanism [20].…”