Dispersion of ordered stripe phases in the cuprates

A phase-separation model is presented for the stripe phase of the cuprates, which allows the doping dependence of the photoemission spectra to be calc ulated. The idealized limit of a well-ordered array of magnetic and charged stripes is analyzed, including effects of long-range Coulomb repulsion. Re markably, down to the limit of two-cell-wide stripes, the dispersion can be interpreted as essentially a superposition of the two end-phase dispersion s, with superposed minigaps associated with the lattice periodicity. The la rgest minigap Tails near the Fermi level; it can be enhanced by proximity t o a (bulk) van Hove singularity. The calculated spectra are dominated by tw o features: this charge stripe minigap plus the magnetic stripe Hubbard gap . There is a strong correlation between these two features anti the experim ental photoemission results of a two-peak dispersion in La2-xSrxCuO4 and th e peak-dip-hump spectra in Bi2Sr2CaCu2O8+delta. The differences are suggest ive of the role of increasing stripe fluctuations. The 1/8 anomaly is assoc iated with a crossover from magnetic-dominated to charge-dominated stripes. A model is proposed for the limiting minority magnetic phase as an isolate d two-leg ladder.