Spin-Hole Model with Magnetic Vortex-Antivortex Pairing Mechanism for Doped La2CuO4

  • A. Robledo
  • C. Varea

Abstract

The introduction of charge carriers in La2CuO4 can be achieved either by raising oxygen stoichiometry or by cation substitution, typically via the replacement of La+3 by Sr+2 or Ba+2 .1 The presence of charge carriers , which appear as electron holes on the CuO2 planes, has a profound effect on the properties of the system. Increasing their numbers beyond a low-lying threshold ( x≈0.06 in La2−xSrxCuO4) transforms the initial insulating (I) (and antiferromagnetic (AF) at low temperature) state into a metallic (M) ( superconductive (SC) at low temperature) state, and this exhibits an unusual, and not yet fully characterized, magnetic behavior .2 Doping induces, too, structural changes, the most aparent of which is a transformation from an orthorhombic (O) to a tetragonal (T) structure observable at temperatures as high as 530 K when close to the undoped limit. 1,2 There are indications of other, still incompletely resolved transformations,3 closer to , or within, the SC region of the phase diagram. The interplay between superconductivity, magnetism and structure in doped La2CuO4 is the focus of continuing investigations.

Keywords

Vortex Anisotropy Coherence 

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Copyright information

© Plenum Press, New York 1990

Authors and Affiliations

  • A. Robledo
    • 1
  • C. Varea
    • 2
  1. 1.Instituto de FísicaUniversidad Nacional Autónoma de MéxicoMéxico, D.F.Mexico
  2. 2.Facultad de QuímicaUniversidad Nacional Autónoma de MéxicoMéxico, D.F.Mexico

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