Insititute of Bio- and Nanosystems II
Forschungszentrum Jülich GmbH
Leo-Brandt-Strasse
D-52425 Jülich, Germany
contact:  Roger Wördenweber

 

Vortex matter in micro- and nanostructured superconducting films - towards novel fluxon devices

Nanostructured superconductors and vortex dynamics represent a major activity of 'Functional Oxide Films and Sensors' . The activity is part of international network and national research programs.

Experimental and theoretical studies of nano- and mesoscopic systems represents one of the challenging goals of research, due to perspectives of application of nanostructures in micro- and nanoelectronics as well as due to new insight in fundamental problems arising at boundaries or in low-dimensional systems. In this context the understanding of vortex matter in mesoscopic patterned superconducting thin films is considered
The progress in fabrication of thin film nanostructures made it possible to fabricate complex superconducting samples with lateral extensions smaller than several nm or large regular arrays consisting of practically identical nanostructures. Thus, the analysis of nucleation, penetration and dynamics of vortices in nanostructured superconducting films has gained a lot of interest. It already led to new insight into these processes, which are also relevant for the understanding of the behavior of any 'extended' superconducting devices.

Array of antidots in YBCO films

In this project, vortex matter in nanostructured high-Tc superconducting films and systems are examined. The work is intended to add to the fundamental understanding of these systems, improve existing applications, and lead to new device concepts. At present we concentrate on the understanding of the impact and use of artificial defects, mesoscopic holes (antidots) or magnetic dots. Special arrangements of antidots in high-Tc films and devices are used for

  • trapping of magnetic flux
  • guided motion of magnetic flux
  • directional dependent motion of flux (diode or ratchet effect)

at low and high frequencies. Next to the basic understanding of the mechanism of flux behavior in nanostructured superconductors and at high frequencies (up to several GHz), these effects are of interest for

  • optimization of existing superconducting devices (see for instance the noise reduction in high-Tc SQUIDs)
  • development and demonstration of novel fluxon concepts (e.g., vortex ratchet, or flux manipulators)

References:

M. P. González, E. Hollmann and R. Wördenweber
Quantitative analysis of the guidance of vortices in superconducting films with magnetic dots
J. Appl. Phys. 102, 63904 (2007)

R. Wördenweber, J.S.K. Sankarraj, P. Dymashevski and E. Hollmann
Anomalous Hall effect studied via guided vortex motion
Physica C 434, 101-104 (2006)

A. Lukashenko, A. V. Ustinov, A. P. Zhuravel, E. Hollmann, and R. Wördenweber
Laser scanning microscopy of guided vortex flow in microstructured high-Tc films
J. Appl. Phys. 100, 023913 (2006)

P. Lahl and R. Wördenweber
Fundamental microwave-power-limiting mechanism of epitaxial high-temperature superconducting thin-film devices
J. Appl. Phys. 97, 113911 (2005)

R. Wördenweber
Vortex matter and superconducting electronic devices (overview)
High Temperature Superconductivity 2, Springer Verlag (2004) edt. A. V. Narlikar, p. 363 -411

R. Wördenweber, P. Dymashevski, and V. R. Misko
Guidance of Vortices and Vortex Ratchet Effect in High-Tc Superconducting Thin Films obtained with Special Arrangements of Antidots
Phys. Rev. B 69, 184504 (2004)

M. Pannetier, R. J. Wijngaarden, I. Fløan, J. Rector, R. Griessen, P. Lahl, R. Wördenweber
Unexpected fourfold symmetry in the resistivity of patterned superconductors
Phys. Rev. B 67, 212501 (2003)

R. Wördenweber, P. Selders
Reduction of low-frequency noise in high-Tc SQUIDs by artificial defects
Physica C 366 (2002) 135-148

P.Lahl, R. Wördenweber
Probing microwave properties of high-Tc films via small dc magnetic fields
Appl. Phys. Lett. 81, 505 (2002)
letzte Änderung 01.08.2008 | | Ausdrucken