Evidence for Intra-Unit-Cell magnetic order in Bi2Sr2CaCu2O8+d

TL;DR

This study provides neutron scattering evidence of intra-unit-cell magnetic order in Bi2Sr2CaCu2O8+d, indicating time reversal symmetry breaking within the pseudogap phase of high-temperature cuprate superconductors.

Contribution

It demonstrates the presence of intra-unit-cell magnetic order in Bi2Sr2CaCu2O8+d using polarized neutron scattering, extending previous findings to this bilayer cuprate.

Findings

Evidence of intra-unit-cell magnetic order in Bi2Sr2CaCu2O8+d

Magnetic order shows time reversal symmetry breaking

Order is consistent with other cuprate pseudogap states

Abstract

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.