Magnetic order in the pseudogap phase of high-$T_C$ superconductors

摘要

One of the leading issues in high-$T_C$ superconductors is the origin of thepseudogap phase in underdoped cuprates. Using polarized elastic neutrondiffraction, we identify a novel magnetic order in the YBa$_2$Cu$_3$O$_{6+x}$system. The observed magnetic order preserves translational symmetry asproposed for orbital moments in the circulating current theory of the pseudogapstate. To date, it is the first direct evidence of an hidden order parametercharacterizing the pseudogap phase in high-$T_C$ cuprates.