Mobile Antiphase Domains in Lightly Doped Lanthanum Cuprate

Light hole doping of lanthanum cuprate strongly suppresses the onset of antiferro-magnetic (AF) order. Surprisingly, it simultaneously suppresses the extrapolated zero temperature sublattice magnetization. 139La NQR results in-lightly doped La2Cu1−xLixO4 demonstrate that these effects are independent of the details of the mobility of the added holes. We propose a model in which doped holes phase separate into charged domain walls that surround “antiphase” domains. These domains are mobile down to ∼30 K, at which point they either become pinned to the lattice or evaporate as their constituent holes become pinned to dopant impurities.