Magnetoresistance in HTSC far above Tc: fluctuations versus normal-state contributions

W. Lang, G. Heine, W. Liebich, X. L. Wang, X. Z. Wang

Publications: Contribution to bookChapter

Abstract

We discuss the temperature dependence of the anisotropic magnetoresistance in high temperature superconductors with a focus on the magnetoresistance at temperatures significantly above T/sub c/. Recent results on YBa/sub 2/Cu/sub 3/O/sub 7- delta / thin films and single crystals are analyzed and measurements of the in-plane and out-of-plane magnetoresistance in optimally doped Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8+x/ single crystals are reported. The in-plane magnetoresistance of both YBa/sub 2/Cu/sub 3/O/sub 7- delta / and Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8+x/ is positive for magnetic fields oriented perpendicular and parallel to the current. The out-of-plane magnetoresistance of Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8+x/ is negative from 94 to 180 K. The results are discussed considering the magnetic-field suppression of superconducting fluctuations including the Aslamazov-Larkin and Maki-Thompson terms, the normal-state magnetoresistance of quasiparticles, and the reduction of the quasiparticle density of states due to condensation into superconducting fluctuations. A crossover from fluctuation-induced in-plane magnetoresistance close to T/sub c/ to the quasiparticle effect was found around 1.25 T/sub c/. The out-of-plane magnetoresistance is dominated by the density-of-states contribution. All results indicate that superconducting fluctuations persist up to at least 2T/sub c/.
Original languageEnglish
Title of host publicationFluctuation Phenomena in High Temperature Superconductors
Subtitle of host publicationProceedings of the NATO Advanced Research Workshop on Fluctuation Phenomena in High Critical Temperature Superconducting Ceramics, Trieste, Italy, 5-9 August 1996
EditorsMarcel Ausloos, Andrei A. Varlamov
Place of PublicationDordrecht
PublisherKluwer Academic Publishers
Pages81-90
Number of pages10
ISBN (Electronic)978-94-011-5536-6
ISBN (Print)978-94-010-6331-9
DOIs
Publication statusPublished - 1997

Publication series

SeriesNATO Science Series. Partnership Sub-Series 3: High Technologies
Volume32

Austrian Fields of Science 2012

  • 103018 Materials physics

Keywords

  • barium-compounds; bismuth-compounds; calcium-compounds; fluctuations-in-superconductors; high-temperature-superconductors; magnetoresistance-; strontium-compounds; superconducting-thin-films; yttrium-compounds magnetoresistance-; HTSC-; fluctuations-; normal-state-contributions; temperature-dependence; anisotropic-magnetoresistance; high-temperature-superconductors; YBa-sub-2-Cu-sub-3-O-sub-7-delta-; Bi-sub-2-Sr-sub-2-CaCu-sub-2-O-sub-8+x-; magnetic-field-suppression; superconducting-fluctuations; quasiparticle-density-of-states; 94-to-180-K; YBa-sub-2-Cu-sub-3-O-sub-7-; Bi-sub-2-Sr-sub-2-CaCu-sub-2-O-sub-8-

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