The stripe-liquid phase in cuprates and nickelates

Abstract
It is well established that doped 2D antiferromagnets such as layered nickelates and certain cuprates can exhibit an ordered phase in which charge carriers are segregated to periodically-spaced domain walls separating antiferromagnetic domains. An open question concerns the nature of the state that is achieved when a stripe solid melts. Recent neutron scattering experiments on nickelates and cuprates indicate that melting leads to a stripe-liquid state; these results will be presented and discussed. The existence of the stripe-liquid phase in nickelates makes it plausible to interpret the mid-infrared absorption in terms of transitions from valence to mid-gap states associated with the stripes.