Magnetic flux penetration in Nb superconducting films with lithographically defined microindentations
| Autor: | Benoît Vanderheyden, Ngoc Duy Nguyen, Philippe Vanderbemden, Jonathan I. Avila, M. Motta, Alejandro Silhanek, W.A. Ortiz, O.-A. Adami, Roman B. G. Kramer, Jérémy Brisbois |
|---|---|
| Přispěvatelé: | Département de Physique, Université de Liège, Departamento de Fisica Universidade Federal de Sao Carlos, Universidade Federal de Sao Carlos, Department of Electrical Engineering & Computer Science, Circuits électroniques quantiques Alpes (QuantECA ), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]) |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Superconductivity
Flux pinning Materials science Condensed matter physics Demagnetizing field Nucleation Nanotechnology 02 engineering and technology Thermomagnetic convection 021001 nanoscience & nanotechnology 01 natural sciences Magnetic flux [PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con] Condensed Matter::Materials Science Indentation 0103 physical sciences Streamlines streaklines and pathlines 010306 general physics 0210 nano-technology ComputingMilieux_MISCELLANEOUS |
| Zdroj: | Physical Review B Physical Review B, American Physical Society, 2016, 93 (5), pp.054521. ⟨10.1103/PhysRevB.93.054521⟩ |
| ISSN: | 2469-9950 2469-9969 |
| DOI: | 10.1103/PhysRevB.93.054521⟩ |
| Popis: | We present a thorough investigation by magneto-optical imaging of the magnetic flux penetration in Nb thin films with lithographically defined border indentations. We demonstrate that discontinuity lines ($d$ lines), caused by the abrupt bending of current streamlines around the indentations, depart from the expected parabolic trend close to the defect and depend on the shape and size of the indentation as well as on the temperature. These findings are backed up and compared with theoretical results obtained by numerical simulations and analytical calculations highlighting the key role played by demagnetization effects and the creep exponent $n$. In addition, we show that the presence of nearby indentations and submicrometer random roughness of the sample border can severely modify the flux front topology and dynamics. Strikingly, in contrast to what has been repeatedly predicted in the literature, we do not observe that indentations act as nucleation spots for flux avalanches, but they instead help to release the flux pressure and avoid thermomagnetic instabilities. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|