Negative Magnetoresistance in Amorphous Indium Oxide Wires

Abstract

We study magneto-transport properties of several amorphous Indium oxide nanowires of different widths. The wires show superconducting transition at zero magnetic field, but, there exist a finite resistance at the lowest temperature. The R(T) broadening was explained by available phase slip models. At low field, and far below the superconducting critical temperature, the wires with diameter equal to or less than 100 nm, show negative magnetoresistance (nMR). The magnitude of nMR and the crossover field are found to be dependent on both temperature and the cross-sectional area. We find that this intriguing behavior originates from the interplay between two field dependent contributions.

Superconducting MoSi nanowires

“…3). The phenomenon is typical for wires in the regime of high QPS rate [36,37,46,22] and has been considered as a fingerprint of phase-slip-dominated dissipation [47]. The effect has several possible explanations [48,49,35,47], but no commonly accepted model exists yet.…”

“…The other parameters used in the fits were normal state resistances and superconducting critical temperatures; R Negative magnetoresistance is observed in the thinnest wire (inset figure 3). The phenomenon is typical for wires in the regime of high QPS rate [22,36,38,45] and has been considered as a fingerprint of phase-slip-dominated dissipation [46]. The effect has several possible explanations [35,[46][47][48], but no commonly accepted model exists yet.…”

Quantum phase transition from superconducting to insulating-like state in a pressurized cuprate superconductor

“…These results are reminiscent of what has been seen in disordered superconducting films. When the film samples move into an insulating state (driven by the magnetic field) from a superconducting state, a positive MR value indicating a superconducting fluctuation state exists on increasing the field [33][34][35] . These results lead us to consider that the positive MR effect may be a universal feature manifesting the existence of a superconducting fluctuation in the insulating state induced either by a magnetic field in the film samples or pressure in the bulk cuprates.…”

Current dependence of the negative magnetoresistance in superconducting NbN nanowires

“…Each fluctuation is associated with a phase slip of 2π, thus inducing voltage according to the Josephson relation V = h 2e ∂ϕ ∂t . Fluctuations have been also considered as the origin of the negative magnetoresistance (nMR) effect 7-9 found in a wide variety of 1D superconductors 7,[10][11][12][13][14][15][16][17][18][19][20][21] . A phenomenological model by Arutyunov 8 explains the nMR as originating from a competition between two mechanisms: thermodynamic fluctuations of the order parameter and quasiparticles (qp) charge imbalance which accompanies each phase slip event.…”

“…Apparently, both processes depend not only on the magnetic field but also on temperature and the transport current. Yet, while most of the published experimental results describe the temperature dependence of the nMR measured at a certain constant current 7,10,12,[14][15][16]21 data on the effect of the current on the nMR is scarce 17 . In the present study we experimentally explore the influence of transport current on the nMR in amorphous quasi-1D NbN wires.…”