Suppression of superconductivity in thin Nb nanowires fabricated in the vortex cores of superfluid helium

Гордон, Е. Б.; Bezryadin, Alexey; Karabulin, A. V.; Matyushenko, V. I.; Khodos, I. I.

doi:10.1016/j.physc.2015.06.010

Cited by 5 publications

(5 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Phase slip phenomena are receiving great attention in literature both for one-dimensional (1D) and two-dimensional (2D) systems. The interest for 1D superconducting strips or nanowires is due to the fact that, for instance, they can undergo quantum phase slip that is topological quantum fluctuations of the superconducting order-parameter field through which tunneling occurs between current-carrying states 2–7 . Recently, the regime when fluctuations induced switching processes are due to multiple phase slip (MPS) events has emerged as observed in 1D wires 2,3,8–10 .…”

Section: Introductionmentioning

confidence: 99%

Superconductor to resistive state switching by multiple fluctuation events in NbTiN nanostrips

Ejrnæs

Salvoni

Parlato

et al. 2019

Sci Rep

View full text Add to dashboard Cite

We report on measurements of the switching current distributions on two-dimensional superconducting NbTiN strips that are 5 nm thick and 80 nm wide. We observe that the width of the switching current distributions has a non-monotonous temperature dependence, where it is constant at the lowest temperatures up to about 1.5 K, after which it increases with temperature until 2.2 K. Above 2.5 K any increase in temperature decreases the distribution width which at 4.0 K is smaller than half the width observed at 0.3 K. By using a careful analysis of the higher order moments of the switching distribution, we show that this temperature dependence is caused by switching due to multiple fluctuations. We also find that the onset of switching by multiple events causes the current dependence of the switching rate to develop a characteristic deviation from a pure exponential increase, that becomes more pronounced at higher temperatures, due to the inclusion of higher order terms.

show abstract

Section: Introductionmentioning

confidence: 99%

Superconductor to resistive state switching by multiple fluctuation events in NbTiN nanostrips

Ejrnæs

Salvoni

Parlato

et al. 2019

Sci Rep

View full text Add to dashboard Cite

show abstract

“…formula (2). The structures of nanowires made of W, Mo, Pt and InPb alloy were taken from our papers [30][31][32].…”

Section: Figure 2 the Comparison Of The Experimental Nanowires Diamet...mentioning

confidence: 99%

“…Some characteristics of the metals studied in this paper. T melt and C p are tabulated values for bulk materials [32]. T ad -adiabatic temperature of the 1 nm -diameter cluster formed by fusion of two cold smaller clusters, D clust -the diameter of the cluster formed by merging of two cold identical spherical clusters, which has a temperature T = T melt , λ max (T melt ) and λ max (T ad ) -wavelengths, corresponding to maximal black-body emission for T = T melt and T = T ad , correspondingly.…”

Section: The Choice Of the Objectsmentioning

confidence: 99%

Non-isothermal physical and chemical processes in superfluid helium

Гордон

Kulish

Karabulin

et al. 2017

Low Temperature Physics

View full text Add to dashboard Cite

Metal atoms and small clusters introduced into superfluid helium (He II) concentrate there in quantized vortices to form (by further coagulation) the thin nanowires. The nanowires' thickness and structure are well predicted by a double-staged mechanism. On the first stage the coagulation of cold particles in the vortex cores leads to melting of their fusion product, which acquires a spherical shape due to surface tension. Then (second stage) when these particles reach a certain size they do not possess sufficient energy to melt and eventually coalesce into the nanowires.Nevertheless the assumption of melting for such refractory metal as tungsten, especially in He II, which possesses an extremely high thermal conductivity, induces natural skepticism. That is why we decided to register directly the visible thermal emission accompanying metals coagulation in He II. The brightness temperatures of this radiation for the tungsten, molybdenum, and platinum coagulation were found to be noticeably higher than even the metals' melting temperatures. The region of He II that contained suspended metal particles expanded with the velocity of 50 m·s -1 , being close to the Landau velocity, but coagulation took place even more quickly, so that the whole process of nanowire growth is completed at distances about 1.5 mm from the place of metal injection into He II. High rate of coagulation of guest metal particles as well as huge local overheating are associated with them concentrating in quantized vortex cores. The same process should take place not only for metals but for any atoms, molecules and small clusters embedded into He II.

show abstract

“…Understanding of this shortcoming has allowed us to create a new design, where spherical inclusions in nanowires are absent, and the length of individual nanowires in a nanoweb is significantly higher than in the original method. 21 That will be especially important in the studies of different size effects, for example in superconductivity 22 or in quantum phase shift. 23 Finally the main conclusion of this study can be represented graphically in Figure 6.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Coagulation of Metals in Superfluid and Normal Liquid Helium

et al. 2017

Self Cite

View full text Add to dashboard Cite

The thermal emission study in this work has shown that coagulation of metals in liquid helium is accompanied by enormous local overheating of several thousand degrees. Direct experiments demonstrated, for the first time, that condensation of metals in superfluid helium occurs via the specific mechanism which is substantially faster than that in normal liquid helium. It has been stated that coagulation of metals in superfluid helium indeed occurs in two stages, a "hot" one of nanoparticles coalescence with the formation of molten nanospheres and the subsequent stage of their sticking together into nanowires. It turned out that if a laser ablation of metal targets immersed in superfluid helium was used for introducing a metal into liquid, the formation of nanowires occurs at distances of only about 1 mm from the laser focus. This leads to the presence of a considerable number of spherical inclusions in nanowires grown in such a way.

show abstract

Suppression of superconductivity in thin Nb nanowires fabricated in the vortex cores of superfluid helium

Cited by 5 publications

References 30 publications

Superconductor to resistive state switching by multiple fluctuation events in NbTiN nanostrips

Superconductor to resistive state switching by multiple fluctuation events in NbTiN nanostrips

Non-isothermal physical and chemical processes in superfluid helium

Coagulation of Metals in Superfluid and Normal Liquid Helium

Contact Info

Product

Resources

About