Magnetic Neutron Scattering in Hole-Doped Cuprate Superconductors

Abstract

A review is presented of the static and dynamic magnetic properties of hole-doped cuprate superconductors measured with neutron scattering. A wide variety of experiments are described with emphasis on the monolayer La2−x(Sr,Ba)xCuO4 and bilayer YBa2Cu3O6+x cuprates. At zero hole doping, both classes of materials are antiferromagnetic insulators with large superexchange constants of J > 100 meV. For increasing hole doping, the cuprates become superconducting at a critical hole concentration of xc=0.055. The development of new instrumentation at neutron beam sources coupled with the improvement in materials has lead to a better understanding of these materials and the underlying spin dynamics over a broad range of hole dopings. We will describe how the spin dispersion changes across the insulating to superconducting boundary as well as the static magnetic properties which are directly coupled with the superconductivity. Experiments directly probing the competing magnetic and superconducting order parameters involving magnetic fields, impurity doping, and structural order will be examined. Correlations between superconductivity and magnetism will also be discussed.

Magnetic order tuned by Cu substitution in Fe1.1−zCuzTe

“…The magnetic ordering is similar to a low-temperature extrapolation of the incommensurate phase of the Fe In many of the Cu-and Fe-based superconductors, superconductivity develops concomitantly with the suppression of the structural phase transition and antiferromagnetic order. 5,6 This also holds for Fe 1+y Te 1−x Se x . When Se is used to replace Te, the lattice distortion and antiferromagnetic order are suppressed, followed by the appearance of bulk superconductivity with x 0.3.…”

Two-dimensional incommensurate and three-dimensional commensurate magnetic order and fluctuations in La2−xBaxCuO

“…The 214 family of cuprates, La 2−x Ba x CuO 4 , and La 2−x Sr x CuO 4 , are among the most studied of the high temperature superconductors (HTS) [1][2][3] . Most of this work has focussed on La 2−x Sr x CuO 4 , which has been available in large, pristine single crystal form for some time 4 .…”

Superconductivity inLaFe1−xCoxAsO

“…It is interesting to compare and contrast the behavior of the new iron arsenide superconductors with the cuprates. For high-T c copper oxides, the parent compounds are antiferromagnetic Mott insulators [11], and the magnetic order is suppressed and superconductivity emerges by doping with either electrons or holes [12]. Much like copper oxide superconductors, high-T c in the Fe-based family of RFeAsO (R = rare-earth) is caused by doping.…”