TEMPERATURE-INDUCED MOMENTUM-DEPENDENT SPECTRAL WEIGHT TRANSFER IN BI2SR2CACU2O8+DELTA

Angle-resolved photoemission data from the cuprate superconductor Bi2S r2CaCu2O8+delta above and below the superconducting transition tempera ture T-c reveal momentum-dependent changes that extend up to an energy of about 0.3 electron volt, or 40kT(c) (where k is the Boltzmann cons tant). The data suggest an anomalous transfer of spectral weight from one momentum to another, involving a sizable momentum transfer Q simil ar to (0.45 pi, 0). The observed Q is intriguingly near the charge-ord er periodicity required if fluctuating charge stripes are present.