Origin of Charge-Orbital Order in the Half-Doped Manganites

URL:http://link.aps.org/doi/10.1103/PhysRevLett.88.197201 DOI:10.1103/PhysRevLett.88.197201The microscopic origin of the charge and orbital order in the half-doped manganites is examined from ab initio density-functional calculations and exact diagonalization studies. It is shown that the dominant mechanism responsible for the charge order is the Jahn-Teller coupling, with a lesser but significant contribution from the on-site Coulomb interaction. The band structure shows a sizable interchain coupling between the zigzag chains, leading to a considerable band dispersion normal to the chains, in sharp contrast with the zigzag chain physics.We acknowledge support of this work by the U.S. Department of Energy (DE-FG02-00ER45818)