Abstract
We have investigated the effects of structure change and electron correlation on single crystals using angle-resolved photoemission spectroscopy. We show that the cubic to tetragonal phase transition at 105 K is manifested by a charge transfer from in-plane ( and ) bands to out-of-plane band, which is opposite to the theoretical predictions. Along this second-order phase transition, we find a smooth evolution of the quasiparticle strength and effective masses. The in-plane band exhibits a peak-dip-hump lineshape, indicating a high degree of correlation on a relatively large (170 meV) energy scale, which is attributed to the polaron formation.
- Received 8 February 2010
DOI:https://doi.org/10.1103/PhysRevB.81.235109
©2010 American Physical Society