Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · cond-mat/0511508

Discrete model analysis of the critical current density measurements in superconducting thin films by a single coil inductive method

M. Aurino·E. Di Gennaro·F. Di Iorio·A. Gauzzi·G. Lamura·A. Andreone
View original source ↗Read source document ↗Export metadata ↓

Abstract

The critical current density of a superconducting film can be easily determined by an inductive and contactless method. Driving a sinusoidal current in a single coil placed in front of a superconducting sample, a non zero third harmonic voltage V_3 is induced in it when the sample goes beyond the Bean critical state. The onset of V_3 marks the value of current beyond which the sample response to the magnetic induction is no more linear. To take into account, in a realistic way, the magnetic coupling between the film and the coil we have developed a discrete model of the inducing and induced currents distribution. In the framework of this model the magnetic field profile on the sample surface and the coefficient linking the current flowing in the coil and the critical current density J_C of superconducting thin films is evaluated. The numerical results are checked measuring J_C of several thin films of YBa_2Cu_3O_(7-d) of known superconducting properties, used as a control material.

Explore related subjects

cond-mat.supr-con

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M. Aurino, E. Di Gennaro, F. Di Iorio, A. Gauzzi, G. Lamura, A. Andreone. 2005-11-21. Discrete model analysis of the critical current density measurements in superconducting thin films by a single coil inductive method. https://doi.org/10.1063/1.2142097

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Same-spin correlation screens the exchange peak of the electron gas near 2kF

Exchange alone gives the electron gas a local field factor with a sharp peak just below 2kF. Quantum Monte Carlo finds none. Both spin channels are computed here from their lowest diagrams with a dynamically screened interaction and no fitting. Parallel spin correlation is the negative image of exchange and removes about half the peak; the calculated spin-resolved factors account for the QMC data at rs = 1 and 2, and at q = 0 for the compressibility and spin susceptibility obtained from the ground-state energy. The two classes of diagrams are the two terms of the kernel of Hedin's vertex equation, of which the second is routinely dropped.

cond-mat.supr-con↗
arXiv2026

Local Josephson response near nonmagnetic impurities and vortices in a two-orbital $s_{\pm}$ superconductor

We study the local Josephson response near nonmagnetic impurities and vortices in a self-consistent two-orbital $s_{\pm}$ superconductor. For a local $s$-wave tip that couples equally to the two orbitals, anomalous spectral contributions of opposite sign nearly cancel in the clean sample. Nonmagnetic impurities redistribute these contributions and can reverse the local coupling without a corresponding $π$ phase shift of the bond pair fields. Negative coupling appears at off-center sites at weaker impurity potentials than at the impurity site. The impurity-induced change is concentrated at lower quasiparticle energies, while states over a broader energy range contribute to the total clean and impurity couplings. In zero field, the coupling also changes sign as the tip gap is varied, and increasing the tunneling strength can reverse the $m=1$ sine component of the current without changing the sample state. At the chosen coherence-peak energy, increasing impurity strength mainly changes the relative intensities of existing quasiparticle-interference features. In a self-consistent two-vortex state, the Josephson response develops a spatially varying phase relative to the condensate. The response and condensate share the winding close to each core, while larger loops enclose additional winding of the Josephson response. The local Josephson sign and phase reflect the anomalous spectrum and the tip--sample coupling.

cond-mat.supr-con↗
arXiv2026

Thermalization-Controlled Superconducting Diode-Like Transport in Disordered Molybdenum and NbN Thin Films

Superconducting diode effects are characterized by direction-dependent critical currents in the superconducting state. Here, we investigate diode-like transport in 128-nm-thick Mo thin film deposited on Si_SiO2 substrate by DC magnetron sputtering. The thin film exhibit a superconducting transition temperature TC of 5.8 K. Pronounced current-direction asymmetry and hysteresis are observed in current-voltage characteristics measured in a closed-cycle refrigerator. In contrast, the same thin film exhibits a substantially more symmetric response in a 14T cryogenic system with improved sample thermalization. We attribute this strong dependence on the measurement environment to electrothermal effects arising from current-induced Joule heating and finite thermal relaxation. As the current approaches the superconducting-to-resistive switching condition, the emergence of a resistive component leads to a rapid increase in Joule heating, raising the sample temperature and modifying the switching condition. Conversely, during the resistive-to-superconducting transition, residual heating and finite thermal relaxation reduce the switching current. Since P is equal to I2R it is independent of current polarity, the observed asymmetry is not associated with polarity-dependent Joule heating but with the interplay of thermal relaxation, sweep history, and thermal boundary conditions. The suppression of the asymmetry under improved thermalization, together with similar behavior observed in NbN reference films, indicates that the apparent diode-like response is strongly influenced by electrothermal effects. These results highlight the need to distinguish thermal switching and hysteresis from intrinsic nonreciprocal superconductivity when identifying superconducting diode effects in transport measurements.

cond-mat.supr-con↗