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arXiv · 1308.1396

Superlattice origin of incommensurable density waves in La_{2-x}Ae_xCuO4 (Ae = Ba, Sr)

Manfred Bucher
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Abstract

In line with the Coulomb-oscillator model of superconductivity, loop currents of excited 3s electrons from O^2- ions, passing in the CuO2 plane through nuclei of nearest-neighbor oxygen quartets, create the antiferromagnetic phase of undoped copper oxides. Holes, introduced by alkaline-earth doping of La2CuO4, destroy the loop currents, thereby weakening antiferromagnetism until it disappears at doping x = 0.02. Further doping of La_2-xAe_xCuO4 gives rise to incommensurate free-hole density waves whose wavelength is determined by the spacing of a doping superlattice. Modulating the ordering of the ions' magnetic moments, the charge-density wave, of incommensurability 2 delta, causes a magnetic density wave of incommensurability delta. The formula derived for delta(x) is in excellent agreement with data from X-ray diffraction and neutron scattering.

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Manfred Bucher. 2013-08-24. Superlattice origin of incommensurable density waves in La_{2-x}Ae_xCuO4 (Ae = Ba, Sr). https://arxiv.org/abs/1308.1396

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