Phase diagram of high-T-c cuprates: Stripes, pseudogap, and effective dimensionality - art. no. 214504

The key problem in the physics of high T-c cuprates [J. G. Bednorz and K. A . Muller, Z. Phys. B 64, 188 (1988)] is whether doping is inhomogeneous and holes are expelled into one-dimensional (ID) stripes. We demonstrate that the scattering mechanism defining the transport properties and the universa l superlinear rho (T) behavior in underdoped YBa2Cu3Ox thin films [J. Vanac ken, Physica B 294-295, 347 (2001)] is the same in spin ladders and underdo ped cuprates. This implies that transport through conducting charge stripes in cuprates is fully controlled by the inelastic length coinciding with th e magnetic correlation length in the ladders, i.e., holes in stripes behave very similarly to holes in spin ladders. The ID stripe transport model des cribes remarkably well the temperature dependences of the resistivity and t he scaling behavior of magnetic and transport properties of underdoped cupr ates (including transport in fields up to 50 T) using essentially one fitti ng parameter-the spin gap-decreasing with hole doping. In the framework of this model the hole-rich stripes are just spin ladders with an even number of chains, and therefore the pseudogap is simply the spin gap in spin ladde rs. The effective dimensionality is 2D at high temperature and ID in the ps eudogap stripe regime. Disorder can lead to a pinning of stripes and their fragmentation, thus enforcing the interstripe hopping which effectively rec overs the 2D transport regime at low temperatures.