SPIN-CHARGE SEPARATION IN SINGLE-CHAIN COMPOUND SR2CUO3 STUDIED BY ANGLE-RESOLVED PHOTOEMISSION

Angle-resolved photoemission measurements were performed for one-dimen sional Sr2CuO3 which consists of single Cu-O chains. Two dispersive ba nds were observed near E-F in the first half of the Brillouin zone (k = 0 to pi/2) of the chain-direction. Both bands have a common maximum point closest to E-F at k = pi/2 while they show different dispersions of about 0.25 and 1 eV, respectively, with a continuous intensity dis tribution in between. The less dispersive band is almost diminished in another half of the Brillouin zone (k = pi/2 to pi). These results ar e consistent with the solution of the one-dimensional Hubbard model as well as the t-J model calculation, suggesting the spin-charge separat ion in the one-dimensional Cu-O chain. The experimental results are co mpared with those of the double-chain compound SrCuO2. (C) 1998 Publis hed by Elsevier Science Ltd.