Vortex dynamics in spacing-graded array of defects on a niobium film

T. C. Wu, Lance Horng, J. C. Wu, C. W. Hsiao, Jan Kolacek, T. J. Yang

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

We have investigated the vortex dynamics in the niobium films having a spacing-graded array of pinning sites. The samples were fabricated by using electron beam lithography through a lift-off technique. The pinning sites of 200 nm in diameter were arranged with a constant hole-defect separation in x-axis direction and graded separation in y-axis direction from 392 nm to 408 nm. The magnetoresistance measurements and current-voltage characteristics were explored with the external magnetic field applied perpendicular to the film plane. Dc current-voltage measured at matching field revealed two distinct curves resulted from the positive and negative applied current directions, respectively. This is believed to be due to an asymmetry pinning potential formed in the spacing-graded array of holes, giving rise to asymmetry Lorentz forces. Dc voltage drop measured with respect to the ac current applied along the x-axis of the sample showed two separated maxima, which can be explained using the dynamics of pinned vortex lattice and interstitial vortices in the asymmetry pinning landscape.

Original languageEnglish
Pages (from-to)353-356
Number of pages4
JournalPhysica C: Superconductivity and its applications
Volume437-438
Issue numberSPEC. ISS.
DOIs
Publication statusPublished - 2006 May 15

Fingerprint

Niobium
niobium
Vortex flow
spacing
vortices
Defects
defects
asymmetry
Lorentz force
electric potential
Electron beam lithography
Magnetoresistance
Current voltage characteristics
Magnetic fields
interstitials
lithography
Electric potential
electron beams
Direction compound
curves

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

Cite this

Wu, T. C. ; Horng, Lance ; Wu, J. C. ; Hsiao, C. W. ; Kolacek, Jan ; Yang, T. J. / Vortex dynamics in spacing-graded array of defects on a niobium film. In: Physica C: Superconductivity and its applications. 2006 ; Vol. 437-438, No. SPEC. ISS. pp. 353-356.
@article{9a93df74636746eaba46940ca26d8fbf,
title = "Vortex dynamics in spacing-graded array of defects on a niobium film",
abstract = "We have investigated the vortex dynamics in the niobium films having a spacing-graded array of pinning sites. The samples were fabricated by using electron beam lithography through a lift-off technique. The pinning sites of 200 nm in diameter were arranged with a constant hole-defect separation in x-axis direction and graded separation in y-axis direction from 392 nm to 408 nm. The magnetoresistance measurements and current-voltage characteristics were explored with the external magnetic field applied perpendicular to the film plane. Dc current-voltage measured at matching field revealed two distinct curves resulted from the positive and negative applied current directions, respectively. This is believed to be due to an asymmetry pinning potential formed in the spacing-graded array of holes, giving rise to asymmetry Lorentz forces. Dc voltage drop measured with respect to the ac current applied along the x-axis of the sample showed two separated maxima, which can be explained using the dynamics of pinned vortex lattice and interstitial vortices in the asymmetry pinning landscape.",
author = "Wu, {T. C.} and Lance Horng and Wu, {J. C.} and Hsiao, {C. W.} and Jan Kolacek and Yang, {T. J.}",
year = "2006",
month = "5",
day = "15",
doi = "10.1016/j.physc.2005.12.047",
language = "English",
volume = "437-438",
pages = "353--356",
journal = "Physica C: Superconductivity and its Applications",
issn = "0921-4534",
publisher = "Elsevier",
number = "SPEC. ISS.",

}

Vortex dynamics in spacing-graded array of defects on a niobium film. / Wu, T. C.; Horng, Lance; Wu, J. C.; Hsiao, C. W.; Kolacek, Jan; Yang, T. J.

In: Physica C: Superconductivity and its applications, Vol. 437-438, No. SPEC. ISS., 15.05.2006, p. 353-356.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Vortex dynamics in spacing-graded array of defects on a niobium film

AU - Wu, T. C.

AU - Horng, Lance

AU - Wu, J. C.

AU - Hsiao, C. W.

AU - Kolacek, Jan

AU - Yang, T. J.

PY - 2006/5/15

Y1 - 2006/5/15

N2 - We have investigated the vortex dynamics in the niobium films having a spacing-graded array of pinning sites. The samples were fabricated by using electron beam lithography through a lift-off technique. The pinning sites of 200 nm in diameter were arranged with a constant hole-defect separation in x-axis direction and graded separation in y-axis direction from 392 nm to 408 nm. The magnetoresistance measurements and current-voltage characteristics were explored with the external magnetic field applied perpendicular to the film plane. Dc current-voltage measured at matching field revealed two distinct curves resulted from the positive and negative applied current directions, respectively. This is believed to be due to an asymmetry pinning potential formed in the spacing-graded array of holes, giving rise to asymmetry Lorentz forces. Dc voltage drop measured with respect to the ac current applied along the x-axis of the sample showed two separated maxima, which can be explained using the dynamics of pinned vortex lattice and interstitial vortices in the asymmetry pinning landscape.

AB - We have investigated the vortex dynamics in the niobium films having a spacing-graded array of pinning sites. The samples were fabricated by using electron beam lithography through a lift-off technique. The pinning sites of 200 nm in diameter were arranged with a constant hole-defect separation in x-axis direction and graded separation in y-axis direction from 392 nm to 408 nm. The magnetoresistance measurements and current-voltage characteristics were explored with the external magnetic field applied perpendicular to the film plane. Dc current-voltage measured at matching field revealed two distinct curves resulted from the positive and negative applied current directions, respectively. This is believed to be due to an asymmetry pinning potential formed in the spacing-graded array of holes, giving rise to asymmetry Lorentz forces. Dc voltage drop measured with respect to the ac current applied along the x-axis of the sample showed two separated maxima, which can be explained using the dynamics of pinned vortex lattice and interstitial vortices in the asymmetry pinning landscape.

UR - http://www.scopus.com/inward/record.url?scp=33745464092&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33745464092&partnerID=8YFLogxK

U2 - 10.1016/j.physc.2005.12.047

DO - 10.1016/j.physc.2005.12.047

M3 - Article

AN - SCOPUS:33745464092

VL - 437-438

SP - 353

EP - 356

JO - Physica C: Superconductivity and its Applications

JF - Physica C: Superconductivity and its Applications

SN - 0921-4534

IS - SPEC. ISS.

ER -