Common Phase Diagram for Antiferromagnetism inLa2−xSrxCuO4andY1−xCaxBa2Cu3O6as Seen by Muon Spin Rotation

Abstract

By zero field muon spin rotation we studied the antiferromagnetic correlations in the single layer system ${\mathrm{La}}_{2\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{CuO}}_{4}$ and the bilayer system ${\mathrm{Y}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{Ba}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{6}$. We observe a common phase diagram as a function of hole doping per plane with two distinct transitions in the magnetic ground state. The first transition marks the border between the 3D antiferromagnetic state and a disordered state with short ranged correlations. The second transition marks a distinct change in the magnetic correlations at the onset of superconductivity.