Vortex variable range hopping in a conventional superconducting film

Abstract

The behavior of a disordered amorphous thin film of superconducting Indium Oxide has been studied as a function of temperature and magnetic field applied perpendicular to its plane. A superconductor-insulator transition has been observed, though the isotherms do not cross at a single point. The curves of resistance vs. temperature on the putative superconducting side of this transition, where the resistance decreases with decreasing temperature, obey two-dimensional Mott variable-range hopping of vortices over wide ranges of temperature and resistance. To estimate the parameters of hopping, the film is modeled as a granular system and the hopping of vortices is treated in a manner analogous to hopping of charges. The reason the long range interaction between vortices over the range of magnetic fields investigated does not lead to a stronger variation of resistance with temperature than that of two-dimensional Mott variable-range hopping remains unresolved.

Sensitivity of the superconducting state in thin films

“…2 ). We conclude that our data do not support the existence of quantum corrections ( 10 , 15 , 34 ) to the well-known transport due to thermally activated vortices ( 5 ).…”

“…2). We conclude that our data do not support the existence of quantum corrections [3,8,32] to the well-known transport due to thermally activated vortices [11].Although the effect the filters have on both systems is qualitatively similar it is important to point out that, while for a:InO it is only seen well below T C , for 2H-NbSe 2 filtering has a measurable effect right from T C , and at B = 0. In Fig.…”

Effect of external electromagnetic radiation on the anomalous metallic behavior in superconducting Ta thin films

“…The exceptionally low roughness generally attributes to the favorable wetting property of Ta thin films on SiO2. The surface roughness of Ta thin films is comparable to 2D crystalline superconductors such as ion-gated ZrNCl [14], and much lower than highly disordered InOx [11]. Ta thin films reported in this study are listed in Table Ⅰ.…”

“…Under a wide range of B, decreasing resistance with thermally activated behavior at relatively high T's transformed to T-independent finiteresistance saturation at low T's. The metallic behavior has been widely reported in various thin films such as highly disordered InOx films [11], weakly disordered Ta films [12], and 2D crystalline films of 2H-NbSe2 [13] and ion-gated ZrNCl [14].…”

Thermal conductivity of strong coupling V$_{1-x}$Ti$_x$ superconductors in the Mott-Ioffe-Regel limit

“…Although superconductivity around Anderson transition has attracted researchers for several decades [2][3][4][5][6][7], the understanding on the nature of the superconductivity is yet to be clear [5][6][7]. These studies became intense after the discovery of high temperature superconductors [8] and the Fe based superconductors [9,10] due to the underlined superconductor to insulator transition (in 2-dimensional materials) as a function of disorder and magnetic field which is thought to be a quantum phase transition [11][12][13][14].…”