Diamagnetic activity above Tc as a precursor to superconductivity in La2-xSrxCuO4 thin films

Ienari Iguchi (), Tetsuji Yamaguchi and Akira Sugimoto
Additional contact information
Ienari Iguchi: Tokyo Institute of Technology
Tetsuji Yamaguchi: Tokyo Institute of Technology
Akira Sugimoto: Tokyo Institute of Technology

Nature, 2001, vol. 412, issue 6845, 420-423

Abstract: Abstract Superconductors show zero resistance to electric current, and expel magnetic flux (the Meissner effect) below the transition temperature (Tc). In conventional superconductors, the ‘Cooper pairs’ of electrons that are responsible for superconductivity form only below Tc. In the unconventional high-Tc superconductors, however, a strong electron correlation is essential for pair formation: there is evidence1,2,3,4,5 that some pairs are formed above Tc in samples that have less than the optimal density of charge carriers (underdoped) and an energy gap—the ‘pseudogap’—appears to be present. Moreover, excitations that look like the vortices that carry magnetic flux inside the superconducting state have been reported above Tc (refs 6, 7). Although the origin of the pseudogap remains controversial8,9,10,11, phase fluctuations above Tc, leading to some form of local superconductivity or local pairing, seem essential9,12,13,14,15,16. Here we report magnetic imaging (scanning SQUID microscopy) of La2-xSrxCuO4 thin films. Clear quantized vortex patterns are visible below Tc (18–19 K), and we observe inhomogeneous magnetic domains that persist up to 80 K. We interpret the data as suggesting the existence of diamagnetic regions that are precursors to the Meissner state.

Date: 2001
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/35086540 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:412:y:2001:i:6845:d:10.1038_35086540

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/35086540

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().