Temperature-Induced Momentum-Dependent Spectral Weight Transfer in Bi 2 Sr 2 CaCu 2 O 8+δ

Abstract
Angle-resolved photoemission data from the cuprate superconductor Bi 2 Sr 2 CaCu 2 O 8+δ above and below the superconducting transition temperature T c reveal momentum-dependent changes that extend up to an energy of about 0.3 electron volt, or 40 kT c (where k is the Boltzmann constant). The data suggest an anomalous transfer of spectral weight from one momentum to another, involving a sizable momentum transfer Q ∼ (0.45π, 0). The observed Q is intriguingly near the charge-order periodicity required if fluctuating charge stripes are present.