Polarized elastic neutron scattering measurements have been performed in the bilayer copper oxide system Bi2Sr2CaCu2O8+d, providing evidence for an intra unit cell (IUC) magnetic order inside the pseudo-gap state. That shows time reversal symmetry breaking in that state as already reported in Bi2Sr2CaCu2O8+d through dichroism in circularly polarized photoemission experiments. The magnetic order displays the same characteristic features as the one previously reported for monolayer HgBa2CuO4+d and bilayer YBa2Cu3O6+x, demonstrating that this genuine phase is ubiquitous of the pseudo-gap of high temperature copper oxide materials.
@article{arxiv.1207.1038,
title = {Evidence for Intra-Unit-Cell magnetic order in Bi2Sr2CaCu2O8+d},
author = {S. De Almeida-Didry and Y. Sidis and V. Baledent and F. Giovannelli and I. Monot-Laffez and P. Bourges},
journal= {arXiv preprint arXiv:1207.1038},
year = {2015}
}