Neutron scattering studies of stripe correlations in curate oxide superconductors

In the last quarter of a century, neutron-scattering measurements have provided important clues for understanding the novel magnetism of carrier doped cuprate oxides. Discovery of evidence for charge-density-wave (CDW) and spin-density-wave (SDW) orders in La1.6−xNd0.4SrxCuO4 with x ∼ 1/8 has attracted much attention on the universality of inhomogeneous carrier distribution in CuO2 planes, namely stripe correlations, and its relevance to the superconductivity. Here we review the nature of charge and spin stripe orders in a prototypical superconducting La-214 system, which has been investigated mainly by neutron scattering measurements. After introducing the hole concentration range, where the each order can be observed, characteristic features of low-energy spin fluctuations in the stripe ordered and disordered La2−xBaxCuO4 with x ∼ 1/8 will be discussed in terms of fluctuating stripes. The impact of magnetic field and impurity substitution on the orders is also presented, followed by a comparative study on electron-doped cuprates. Finally, we will give a brief summary of experimental trends.

► Hole concentration range for the stability of static stripe order is summarized.
► Nature of magnetic excitation is explained from a viewpoint of fluctuating stripes.
► Doped impurity and applied magnetic field stabilize static stripe orders.
► No direct evidence of stripe correlation was detected in electron-doped system.