Resistance and current-voltage characteristics of individual superconductingNbSe2nanowires

Abstract

Resistance and current-voltage characteristics of individual superconducting NbSe 2 nanowires are investigated. In the current-voltage curves, a stairlike structure is observed, indicating the possible formation of phase-slip centers. A close examination of the current-voltage characteristic in a selected high quality NbSe 2 nanowire with a diameter of 75 nm reveals that the characteristic voltages in the stairlike structure follow the BCS-like temperature dependence of superconducting gaps vanishing at T C. While the phase-slip center mechanism remains to be a plausible explanation of the observed features, an alternative model involving multigap Josephson tunneling is proposed to account for the BCS-like temperature dependence. From the BCS fits, two distinct superconducting gaps are extracted. Moreover, the critical current of the 75 nm nanowire at low temperatures as well as near T C can also be described by the Ambegaokar-Baratoff relation for multigap Josephson junctions. Our data suggest the possible observation of multiband superconductivity in NbSe 2 and are in good agreement with the predictions of recent band structure and Fermi surface calculations on NbSe 2 .

Heat transfer at the van der Waals interface between graphene and NbSe2

“…The critical current density is calculated as 8 × 10 5 A/cm 2 for the current application with the metal electrode. The critical current density measured with this contact geometry is in good agreement with that typically observed in NbSe2 due to the Oersted field effect of the current [25].…”

Phase slip lines in superconducting few-layer NbSe 2 crystals

“…12,13 Despite the physical difference, PSLs produce similar current-voltage characteristics (IVC) as PSCs, namely, discontinuous voltage jumps separating linear portions whose extrapolation on the current axis leads to a finite excess current. 9, [14][15][16][17] In ordinary polycrystalline or amorphous superconducting films, it is not easy to observe signatures of PSLs. The main experimental difficulty 15 is to prevent the formation of Abrikosov vortices by keeping a sufficiently high energetic barrier at the edges.…”

“…It was found from numerical simulations based on time-dependent Ginzburg Landau (TDGL) equations [10,11] that PSLs are a sort of rivers of fast vortices and antivortices (called kinematic vortices [11]) that annihilate in the middle of the sample [12,13]. Despite the physical difference, PSLs produce similar currentvoltage characteristics (IVC) as PSCs, namely, discontinuous voltage jumps separating linear portions whose extrapolation on the current axis leads to a finite excess current [9,[14][15][16][17].…”

Noise signal as input data in self-organized neural networks

“…There is a striking similarity between the double-threshold V -I dependences in silicon MOSFET samples and those (with the voltage and current axes interchanged) in the type-II superconductors, where the existence of the vortex lattice has been firmly established [23,24,25,26,27]. An example of I-V characteristic in such a system is shown in Fig.…”