Spontaneous symmetry breaking in vortex systems with two repulsive lengthscales

P. J. Curran, W. M. Desoky, M. V. Milošević, A. Chaves, J. B. Laloë, J. S. Moodera, S. J. Bending

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Scanning Hall probe microscopy (SHPM) has been used to study vortex structures in thin epitaxial films of the superconductor MgB2. Unusual vortex patterns observed in MgB2 single crystals have previously been attributed to a competition between short-range repulsive and long-range attractive vortex-vortex interactions in this two band superconductor; the type 1.5 superconductivity scenario. Our films have much higher levels of disorder than bulk single crystals and therefore both superconducting condensates are expected to be pushed deep into the type 2 regime with purely repulsive vortex interactions. We observe broken symmetry vortex patterns at low fields in all samples after field-cooling from above Tc. These are consistent with those seen in systems with competing repulsions on disparate length scales, and remarkably similar structures are reproduced in dirty two band Ginzburg-Landau calculations, where the simulation parameters have been defined by experimental observations. This suggests that in our dirty MgB2 films, the symmetry of the vortex structures is broken by the presence of vortex repulsions with two different lengthscales, originating from the two distinct superconducting condensates. This represents an entirely new mechanism for spontaneous symmetry breaking in systems of superconducting vortices, with important implications for pinning phenomena and high current density applications.

LanguageEnglish
Article number15569
Pages1 - 9
Number of pages9
JournalScientific Reports
Volume5
Early online date23 Oct 2015
DOIs
StatusPublished - 23 Oct 2015

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broken symmetry
vortices
condensates
single crystals
high current
superconductivity
interactions
disorders
current density
microscopy
cooling
scanning
probes
symmetry
thin films
simulation

Cite this

Curran, P. J., Desoky, W. M., Milošević, M. V., Chaves, A., Laloë, J. B., Moodera, J. S., & Bending, S. J. (2015). Spontaneous symmetry breaking in vortex systems with two repulsive lengthscales. Scientific Reports, 5, 1 - 9. [15569]. https://doi.org/10.1038/srep15569

Spontaneous symmetry breaking in vortex systems with two repulsive lengthscales. / Curran, P. J.; Desoky, W. M.; Milošević, M. V.; Chaves, A.; Laloë, J. B.; Moodera, J. S.; Bending, S. J.

In: Scientific Reports, Vol. 5, 15569, 23.10.2015, p. 1 - 9.

Research output: Contribution to journalArticle

Curran, PJ, Desoky, WM, Milošević, MV, Chaves, A, Laloë, JB, Moodera, JS & Bending, SJ 2015, 'Spontaneous symmetry breaking in vortex systems with two repulsive lengthscales', Scientific Reports, vol. 5, 15569, pp. 1 - 9. https://doi.org/10.1038/srep15569
Curran PJ, Desoky WM, Milošević MV, Chaves A, Laloë JB, Moodera JS et al. Spontaneous symmetry breaking in vortex systems with two repulsive lengthscales. Scientific Reports. 2015 Oct 23;5:1 - 9. 15569. https://doi.org/10.1038/srep15569
Curran, P. J. ; Desoky, W. M. ; Milošević, M. V. ; Chaves, A. ; Laloë, J. B. ; Moodera, J. S. ; Bending, S. J. / Spontaneous symmetry breaking in vortex systems with two repulsive lengthscales. In: Scientific Reports. 2015 ; Vol. 5. pp. 1 - 9.
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